A good informative speech topic is narrow enough to explain completely in your time limit, unfamiliar enough that the room learns something, and solid enough to back with two or three credible sources. The 150 topics below are already narrowed: each one is a question with an answer, not a subject like “space” or “food.” Skim the groups, mark three that make you curious, and test them against the checklist in the last section before you commit.
| Your assignment | Start with | Why it fits |
|---|---|---|
| Your assignmentA 2–3 minute speech | Start withFun and unusual topics (139–150) | Why it fitsOne question, one clear answer |
| Your assignmentA 5–7 minute speech | Start withScience, history or how things work | Why it fitsRoom for three points and sources |
| Your assignmentA speech with visual aids | Start withMachines and systems (37–48) | Why it fitsA diagram does half the explaining |
| Your assignmentA speech about a person | Start withPeople and the work they do (71–80) | Why it fitsA life comes with a built-in order |
| Your assignmentA college public speaking class | Start withGovernment, law and money (91–100) | Why it fitsRewards careful research and sourcing |
| Your assignmentA high school class | Start withAnimals, food and sports | Why it fitsFamiliar subjects with a surprise inside |
Science and nature topics
Science topics are the easiest to keep informative, because the answer exists and you are reporting it. Most of them are “how” or “why” questions, which suggests a cause-and-effect structure.
The body and the brain
- Why you get goosebumps, and what they did for our furrier ancestors
- How your body keeps time without a clock: the circadian rhythm
- What physically changes in the brain when you practice a skill
- Why yawns are contagious, and what scientists still disagree about
- How a vaccine teaches the immune system to recognize a germ
- What happens to the day's memories while you sleep
- How the eye and brain turn light into a picture
- Why food tastes bland when your nose is blocked
- Why muscles ache a day or two after a new workout
- How the body adjusts to thin air at high altitude
- What a fever does, and why the body raises its own temperature
- Why some people are left-handed: what researchers know so far
Animals and plants
Pick one animal and one ability. “Octopuses” is a documentary; “how an octopus changes color” is a speech.
- How an octopus changes its color and the texture of its skin
- How honeybee scouts choose a new home for the swarm
- How migrating birds find their way across continents
- Why cats purr, and why purring doesn't always mean a happy cat
- What the “wood wide web” of fungi is, and what scientists dispute about it
- How tardigrades survive drying out completely
- How a dog's nose picks up scents people can't detect
- Why leaves change color in the fall
- How coral reefs are built, and what coral bleaching is
- How tree rings record the weather of past centuries
- How a Venus flytrap knows when to snap shut
- Why some animals truly hibernate and others only slow down
Earth, weather and space
- How a hurricane forms over warm ocean water
- How a weather forecast is made, from weather balloon to phone app
- What causes the northern lights
- Why the sky is blue and sunsets are red
- How earthquakes are measured, and why scientists moved on from the Richter scale
- How scientists watch a volcano for signs of an eruption
- How we know the Earth is about 4.5 billion years old
- How astronauts eat, sleep and exercise on the International Space Station
- How the James Webb Space Telescope sees in infrared
- What a black hole is, and how astronomers photographed one
- How the Moon and the Sun pull the tides
- Where meteorites come from and how they are identified
Technology and how things work
These are process speeches: something goes in, something happens, something comes out. Put the stages in time order, keep to three or four of them, and draw the whole thing on one slide if your class allows visual aids.
Machines and systems
- How noise-canceling headphones erase sound with more sound
- How a microwave oven heats food
- How GPS works out where you are
- How tap water is cleaned before it reaches your kitchen
- What happens to your recycling after the truck picks it up
- How an elevator's safety brake stops a falling car
- How a traffic light knows a car is waiting
- How a card payment is approved in a few seconds
- How solar panels turn sunlight into electricity
- How the power grid matches supply and demand every second
- How a refrigerator moves heat out of the box
- How a 3D printer builds an object layer by layer
Digital life
- How undersea cables carry the internet between continents
- How a search engine decides which results come first
- How video recommendation algorithms choose what plays next
- How websites check your password without storing it: hashing
- How AI chatbots write text one token at a time
- What happens between pressing send and a text arriving
- How two-factor authentication protects an account
- How deepfakes are made and how they are detected
- What “the cloud” is physically: inside a data center
- How a video game goes from idea to release
- How streaming services keep a video from buffering
- How email spam filters decide what's junk
History and people topics
History speeches organize themselves: tell it in time order. The risk is the opposite one, a timeline with no point. Choose a single event or person and one consequence you can show.
Events and turning points
- How Gutenberg's printing press changed what ordinary people could read
- How the 1918 flu pandemic spread, and what cities learned from it
- What caused the Dust Bowl
- How the Rosetta Stone helped scholars read Egyptian hieroglyphs
- How the Great Fire of London changed the way cities are built
- How Prohibition worked in practice, and why it was repealed
- How the Silk Road moved ideas and inventions, not just goods
- What daily life was like on the Oregon Trail
- How the Berlin Wall went up, and how it came down
- How the Apollo 11 crew got to the Moon and back
People and the work they do
A speech about a person needs a reason the person matters now. A speech about a job works best when you follow one ordinary shift.
- How Ada Lovelace wrote what is often called the first computer program
- Who Mary Anning was, and what she found in the cliffs at Lyme Regis
- How Frederick Douglass used newspapers and speeches against slavery
- How Marie Curie became the first person to win Nobel Prizes in two sciences
- How Katherine Johnson's math supported NASA's early spaceflights
- How Nellie Bly reported from inside an asylum, and what changed afterward
- Who the Navajo Code Talkers were, and why their code held
- What an air traffic controller does during a shift
- What a court interpreter does during a trial
- How smokejumpers parachute in to fight remote wildfires
Origins of everyday things
- Where the QWERTY keyboard came from, and why it stuck
- Why the week has seven days
- How railroads gave us time zones
- Why so many towns claim to have invented the hamburger
- How the modern Olympic Games were revived
- Why American school buses are yellow
- How the alphabet grew out of pictures
- Where emoji came from, and how a new one gets approved
- How daylight saving time started, and why people still argue about it
- Why the marathon is 26.2 miles
Society, culture and food
This is where informative speeches drift into persuasion most often, because the subjects touch money, law and identity. Explain how the thing works, present the main views in their own terms, and leave the verdict to the audience.
Government, law and money
- How a bill becomes a law in the US Congress
- How the Electoral College works
- How a jury is chosen
- What goes into a credit score
- What inflation is and how it is measured
- How compound interest works, explained with one savings account
- How a city builds its annual budget
- How the US census tries to count everyone
- What a labor union does at the bargaining table
- How tipping customs differ around the world
Language, arts and culture
- Why sign languages differ from country to country
- How a new word gets into the dictionary
- Where accents come from
- How a movie gets its rating in the US
- How experts tell a real painting from a forgery
- How hip-hop grew out of block parties in the Bronx
- How subtitles and dubbing are made for a foreign film
- How the Day of the Dead is celebrated, and how it differs from Halloween
- How origami designers use math to plan new models
- What a stage manager does on the night of a show
Food and drink
Food topics are good for a first speech: everyone has eaten the subject, and almost nobody knows how it works.
- How a sourdough starter makes bread rise
- Why cutting onions makes you cry
- How coffee goes from a cherry on a shrub to your cup
- How chocolate is made from cacao beans
- What “best by” and “use by” dates on food actually mean
- Why chili peppers feel hot
- How Swiss cheese gets its holes
- How bees make honey, and why it keeps so long
- How a restaurant kitchen is organized: the brigade system
- Why popcorn pops
Health, sports and everyday skills
Health topics come with a responsibility: report what the research says, name where it comes from, and avoid giving medical advice. Sports topics need the opposite care, because half the room knows the rules and half doesn't. Explain for the second half.
Health and habits
- How caffeine keeps you awake, and why it wears off
- How habits form, and why old ones are hard to break
- How the placebo effect works
- What happens to blood after you donate it
- How hands-only CPR keeps blood moving
- What the research says about screens and sleep
Sports and games
- How the offside rule works in soccer
- How a pitcher makes a curveball curve
- How a chess engine chooses its move
- How Paralympic athletes are classified
- How downforce keeps a Formula 1 car on the track
- How the Tour de France works: stages, teams and jerseys
Everyday know-how
These sit close to a demonstration speech. If your assignment wants you to show a skill step by step, see the separate list of demonstration speech topics.
- How to read a nutrition label
- How to read a topographic map
- How to spot a phishing email
- How fact-checkers verify a viral claim
- How public libraries lend e-books
- What a home inspector checks before a house is sold
Fun and unusual topics
Short speeches reward a single surprising answer. Each of these has one, which makes them good for a two- or three-minute slot or a first speech in front of a new class.
- Why the same stock scream turns up in so many movies
- Where fortune cookies really come from
- How a crossword puzzle is built
- How Lego bricks made decades apart still fit together
- How the Svalbard seed vault stores backup copies of the world's crop seeds
- Why people heard different words in the “Yanny or Laurel” clip
- How lost luggage finds its way back to its owner
- How hot-air balloon pilots steer without a steering wheel
- How paper money is protected against counterfeiting
- Why bacteria are slowly eating the Titanic
- How escape rooms are designed
- Why some towns become ghost towns
Turn a topic into a speech
A topic is a starting point. Test it first, then five steps turn it into something you can outline tonight.
Test the topic first
Spend ten minutes on this before you spend ten hours on research. A topic that fails two of these is worth swapping now.
From topic to outline
- Narrow it to one question
Nearly every topic here starts with how, why, what or who for a reason: each one has an answer, and the answer is your speech. If you started from a broad subject such as volcanoes, keep asking how, why or what until you can state the answer in one sentence.
- Write the specific purpose
Finish the sentence “To inform my audience…” with the answer you found. Many instructors ask for this line on the outline, and it keeps you honest: if the verb you want is “convince,” you are writing a persuasive speech.
- Choose three main points and an order
Three points are easy for listeners to hold without notes. Order them by time for processes and events, by place for objects and locations, by subtopic for concepts, and by cause and effect for “why” questions.
- Budget the words
A comfortable speaking pace is roughly 100 to 150 words a minute. At about 130, a five-minute speech is around 650 words: a short opening, three points of about 150 words each, and a close. Read the draft aloud with a timer before you trust any count.
- Find sources you can name aloud
Two or three solid sources are enough for most class speeches. Say them in the speech (“According to NASA…”). Naming a source is the quickest way to earn the room's trust, which rhetoric calls ethos. Put their facts in your own words, which is what paraphrasing means, and note where each one came from.
Question. What causes the northern lights?
Specific purpose. To inform my class what causes the northern lights and why they are seen mostly near the poles.
Central idea. The northern lights appear when charged particles from the Sun strike gases high in Earth's atmosphere, and Earth's magnetic field steers those particles toward the poles.
Main points.
- The Sun releases a steady stream of charged particles, the solar wind, and stronger bursts during solar storms.
- Earth's magnetic field deflects most of them and funnels some down toward the polar regions.
- When they hit oxygen and nitrogen in the upper atmosphere, the gases glow: oxygen mostly green or red, nitrogen blue and purple.
Opening line. “Some night this winter, the sky over northern Norway will turn green, and the cause will have left the Sun days earlier.”
Sources to look for. NASA's pages on auroras and the NOAA Space Weather Prediction Center.
For more ways to open, see how to start a speech. There is also a full classroom speech on topic 22, tree rings, among these informative speech examples.
Once the outline holds together, move it into the speech outline template, then follow how to write a speech for drafting and rehearsal. Your school or instructor sets the rules on length, sources and outline format, so check the assignment sheet first.
Keep it informative
The same subject can make an informative or a persuasive speech. The difference is where you want the audience to end up.
Informative: explains
- How the Electoral College works
- What the research says about screens and sleep
- How daylight saving time started and why it is debated
- Done when listeners understand
Persuasive: argues
- Why the Electoral College should be abolished
- Why you should put your phone away at 10 p.m.
- Why we should end daylight saving time
- Done when listeners agree or act
Drafting it in Strokes
If you write in Strokes, keep the speech as one project on your machine: a document for sources, one for the outline, one for the script. If your class allows AI help, add the outline to a chat with the AI Assistant and ask whether any main point argues instead of explains, or which terms a classmate would need defined. Version history keeps the five-minute draft when you cut it to three, and the outline exports to PDF or Word if your instructor wants a copy.
Frequently asked questions
What makes a good informative speech topic?
One you can explain completely in your time limit, that your audience doesn't already understand, and that you can support with credible sources. Narrow beats broad: how hurricanes form works better than weather.
What are the types of informative speeches?
Public speaking textbooks usually sort them by subject: speeches about objects, people, events, concepts and processes. Some add issues as a sixth type. A demonstration speech is a process speech in which you show the steps as you explain them.
What is the difference between an informative and a persuasive speech?
An informative speech explains so listeners understand; a persuasive speech argues so they agree or act. You can cover a debated subject informatively if you present each side fairly and leave the conclusion to the audience.
How long should an informative speech be?
As long as your assignment says. As a guide, at about 130 words a minute a three-minute speech is roughly 400 words and a five-minute speech about 650. Pace varies from person to person, so time yourself reading aloud.
Can I use these topics for my class?
Yes. They were written for this page and are free to use. Some instructors keep a list of overused topics, so check yours before you start researching.
