- The Adventure Zone: Balance: the Starblaster crew are all examples of this, because they spent 100 years traveling between planes of existence, their physical age resetting every year. Lucretia is a particularly interesting example of this, because she subsequently gambled away twenty years of her life, so that she's both older and younger than she should look.
- The Angry Video Game Nerd is in his late thirties but could pass for being much younger. James Rolfe also has a daughter in Real Life, thus doubling as an Absurdly Youthful Father.
- Played for laugh with Barbie: Life in the Dreamhouse. In the first episode Barbie says she's celebrating her and Ken's forty-third anniversary, despite the fact she looks no older than 24.
- The Chakona Space setting features the contributor series, Tales of the Folly. While Neal Foster falls into the Really 700 Years Old category, many of his friends and colonists and all 12 of his Rakshani Marines fall neatly into this trope.
- Enrei Islio, 21 in Chaos Fighters II-Chemical Siege is called an 8-year old man due to this trope.
- Dan Avidan from Ninja Sex Party and Game Grumps is in his early 40's, and his partner Ninja Brian is even older (he's even married with a young daughter). In Brian's case you'd know, but looking at Dan (a peppy human Q-tip who's constantly happy) you'd never guess. This of course is before he starts talking about Rush and calling game levels "boards", which is when he shows his age.
- Dawn of a New Age: Oldport Blues:
- Sebastian is only 4'9", which is very short for a seventeen-year-old boy and leads to him getting mistaken for younger than he is.
- Michal is the same height as Sebastian and is also one of the most impulsive and childlike members of the cast, making it easy to forget that he's 16.
- This trope is in full force in Deucalion Chronicles - to the point where it's easier to name characters that actually look their age. Almost everyone stops aging after a certain point, thanks to either natural magic or the alchemical solution Ambrosia. Some Outsiders barely age past puberty. The only exceptions are certain religious groups that refuse Ambrosia and non-CU worlds where it is unavailable.
- If anything in Doki's Chronicles is to go by then Toki and Doki are really somewhere in their eighties or nineties (if not a bit older or younger), as back in the time when these two were born cerebral palsy and selective-mutism were not explainable and were beyond their birth-parents comprehension, except for by a horrible disease (Doki's case) and being a 'good child', as seen and not heard (Toki's case). To further point this out, they should not be able to have babies but did. However, there is a reason as to why the are older than they look and that is because they were frozen when they were 12 and a half years old, drastically slowing down their aging process and causing them to age as if nothing changed.
- Dreamscape: As an immortal vampire, Vampire Lord is much older than his peers.
- Chris Bores, who is known as the infamous Irate Gamer, was born in 1979, making him older than many of his more well-known colleagues and detractors (and is much older than the majority of his audience by nearly 20 years).
- The cast of Is It a Good Idea to Microwave This? are often mistaken for high school age, even in their more recent episodes where the cast is approaching 30.
- Justin "JewWario" Carmical, formerly the oldest employee of That Guy with the Glasses, turned 40 in 2011; he looked to be no older than his early 30s.
- Killerbunnies XI and XII: Kamu and Kanran who has a condition that makes them look like babies but they don't seem to let them stop them in being damn near malicious and that both are old enough to smoke but their ages are never stated.
- In Jeanne's case, this is unclear, as we don't know if she is a child or if she just looks like one.
- We also have Andibea, who's stated to be twenty-two.
- The Kindness of Devils has Hardestadt Delac and Grete Ravenhallow, both of whom look like they're in their 20s despite being hundreds of years old. Delac, in particular, is thousands of years old.
- Mechagodzilla in Monster Island Buddies is actually millions of years old, abit thanks to an accidental time-travelling mishap. Though considering he's a robot, it's easy to miss.
- Despite still technically being a "baby" dragon in My Little Pony: Totally Legit Recap, Spike reveals he is actually old enough to be considered a legal adult by Equestrian standards and even engages in some the more risque actions the other characters partake in. This understandably makes things awkward, after he reveals this to Starlight, who apparently gave him a belly rub off screen, thinking he was just a little kid.Spike: You think that was weird for you?
- The Necro Critic doesn't appear to have aged a single day between his first video (at age 19) and his most recent one (in his 30s).
- The Nostalgia Critic is in his 30s, but still has the same babyface as he did when he was fourteen. Doug takes it to bizarre levels with Donnie DuPre from Demo Reel. The character is 42, but as he's still wearing tight clothes, hiding his hairline with a fedora and only has a little more stubble than usual, he looks late twenties at most.
- Not Always Right:
- One story features a 33-year-old customer who looks like a teenager, trying to buy an M-rated game.Customer: "[...] I even quit drinking because its too much of a hassle to buy beer!"
- In a similar vein, this story has a customer accusing an employee of being a teenager playing hooky. Both the employee and her manager confirm that the employee is 21 years old and a college student but the customer refuses to believe them to the point that she actually calls the police to try and arrest the employee for truancy. Fortunately the police officer realizes this is a bogus charge, and, after verifying the employee's age has the customer banned from their store.
- The same two people again, four years later.
- Spinoff site Not Always Working has several instances of guys being mistaken for pedophiles because their twenty-plus-old girlfriends are mistaken for preteens or young teenagers.
- This convenience store clerk uses this trope to deal with people who don't see why they should have to show their ID to prove they're old enough to buy booze.Clerk: You guess how old I am, and if you get within five years, then Ill take your word for how old you are.
Customer: Okay! Id say youre mid-fifties. If I have to be specific 54.
Clerk: Im 73!
Customer: Beat I guess I'll go get my license, then.
- One story features a 33-year-old customer who looks like a teenager, trying to buy an M-rated game.
- RWBY: In Volumes 2 and 3, Cinder, Mercury and Emerald infiltrate Beacon Academy disguised as visiting students from Haven Academy. While Mercury and Emerald are indicated to be teenagers of the appropriate age (17-21) to infiltrate the school, Cinder is a grown adult and some years older than any of the students. While her true age is unknown, she has no trouble passing as a student without raising suspicions.
- 18-year old Survival of the Fittest character Kimmy Redmond is described as looking about thirteen, which is simply down to physical immaturity rather than anything fantastical. There are also Laeil Burbank, who looks about 16, and Alice Jones, who is commonly mistaken for an elementary school student. A recent addition is V4's Celeste Beaumont, who looks like an under-developed freshman.
- Todd in the Shadows would often mock bad lyrics that sound like they were written by a teenager, but would excuse them believing the person that wrote & sung the song was a teen. Only to find out the person in question was in their mid-to-late 20's (such is the case of Kimberly Perry and Carly Rae Jepson)
- Ultra Fast Pony uses this as a joke. Spike (who is stated to be a "baby dragon" in canon) turns out to be 67 years old.
- At the Superhero School Whateley Academy in the Whateley Universe, Generator (Jade Sinclair) and Warlocke are both fourteen, but look only ten or eleven. Then there's Headmistress Elizabeth Carson, who looks like a hot movie starlet in her early thirties, but is actually over seventy. And there's at least one teacher there who's Really 700 Years Old: Circe. The Circe.
- The Gumdrops stars two actresses in their thirties - Kaireht Yovera and Ingrid Igoe - playing twentysomething college students. Some of the crew members weren't even aware of Ingrid's age until she started joking about being an 80s kid. That being said, the other main cast members (Rebecca Rose Flynn, Corey Patton and Ellen Jones) are in their mid-twenties but look slightly younger.
Older Than They Look / Web Original