"I am old, Gandalf. I don't look it, but I am beginning to feel it in my heart of hearts. Well-preserved indeed! Why, I feel all thin, sort of stretched, if you know what I mean: like butter that has been scraped over too much bread. That can't be right. I need a change, or something."
― Bilbo Baggins (The Lord of the Rings)
"I am still my youthful years of one hundred and thirties thank you."
― Kureha (One Piece)
"I hate to admit it, but I am only a hundred and six."
― Liara T'Soni (Mass Effect)
"I'd rather not say this in front of His Majesty, but I'll have you know I've been alive for decades!"
"Hmph! Well, I've been fighting for this country for over a century!"
― Aisha and Castor (How a Realist Hero Rebuilt the Kingdom)
Though well over fifty years old, Laura Weathermill (Angel) has the appearance of a young woman.
Sir George (Ben 10) is well over a thousand years old.
Grandfather (Codename: Kids Next Door) has been alive ever since the 19th century in the exact same physical state, despite his aged appearance in the 21st century.
Though chronologically in her late forties or early fifties, Miss Martian (DC Comics/Young Justice) is only sixteen by the Martian calendar.
Due to the effects of the Super-Soldier Serum, Captain America is unable to age and remain in his healthy physical prime.
The Flash's (DC Comics) differing metabolism slows his aging.
Mystique (Marvel Comics) uses her shapeshifting abilities to rejuvenate her cells, slowing her aging process dramatically.
Wolverine's (Marvel Comics) regenerative abilities slow his aging dramatically, as he is over 100, yet still in his physical prime.
Half-Vampire Eric Brooks/Blade (Marvel Comics) has a much longer lifespan than a normal human.
Wade Wilson/Deadpool (Marvel Comics) ages slower than the average human due to his healing factor.
Romulus (Marvel Comics) is at least several thousand years old.
Remus (Marvel Comics)
Inheriting his father's healing factor, Akihiro Daken (Marvel Comics) retains the appearance of a young man in his physical prime despite being over 60 years old.
Sabretooth's (Marvel Comics) regenerative abilities slow his aging dramatically, being over about 150 years old.
Thanks to the Infinity Formula, Nick Fury (Marvel Comics) remains in his prime despite chronologically being nearly 100 years old.
Due to his time in the Lost Land, Turok's (Turok: Dinosaur Hunter) aging process has been greatly slowed.
Viltrumites like Thragg (Image Comics) have the potential to live for thousands of years and still be in their physical prime.
Jenny Quantum (WildStorm/DC Comics) stopped aging once she reached adulthood.
Due to having her DNA mutated into a plant-like capabilities basing on solar energy, Poison Ivy's (DC Comics) will live longer and aged slower than regular humans, as long as she maintain absorbing enough solar energy
Due to the potent magic of the Genesis Spell, the Young Guardians cannot physically age past 18.
Tomiko Asahina (From the New World) has slowed her aging dramatically and lived for over 250 years by continually rejuvenating her telomeres.
Like all dwarves, Romilda's (Outbreak Company) aging is static, meaning that her appearance will not change from childhood all the way until she dies, thus making it impossible to tell exactly how old she truly is.