Megan was born to Mr. and Mrs. Uno sometime in the year X14. She attended Woxagon Elementary School in X21. Here, she is already shown to be the best friend of Brittany Boviak. When Rodney tripped the new kid Lloyd Nebulon and made him look like a fool, Megan, along with most of the kids in the classroom, laughed at him and, in the future, she would see him as a loser. She became one of the popular kids alongside Brittany over the next seven years.
Like Brittany and many of the other popular girls, Megan is rude and snobby, even more, snobby than Brittany on most occasions. Megan is probably even more superficial that Brittany when it comes to boys as she could not figure out why Brittany would fall in love with Lloyd and she herself fell in love with Kurt's body, rather than Kurt himself. Megan, like Brittany, is friendly to any girl in Luna Vista regardless whether they're popular or not, but is only friendly with boys who are considerably cool.
- Mr. Uno
- Mrs. Uno
- The Big 1-3 (first non-speaking appearance)
- Double Date
- Caution: Wormhole! (first speaking appearance)
- Daydream Transceiver
- Campout on Zoltan III (cameo)
- Kurtlas the Symbiotic Boy (cameo)
- Android Lloyd
- Nerd from Beyond the Stars
- Girl from the Center of the Universe
- Lloyd Changes His Mind
- Francine's Power Trip (cameo)
- Lloyd's Lost Weekend (cameo)
- The Big Sleepover
- Incident at Luna Vista
- That's Debatable (cameo)
- Love Beam Number 9
- Neither Boy Nor Girl
- Cheery Theerlap, Lloyd
- A Place for Larry
- The Big Feud (cameo)
- At Home with the Bolts
- Heads Up, Blobberts!
- Picture Perfect
- Day One (final speaking appearance)
- Go Crater Worms!
- The Ride Along
- "Like Ew!!! Loser!"
- (To Lloyd) "Sorry, no comprende dorkanese!"
- Megan Uno is voiced by Rachel Crane.
- In "Lloyd's Lost Weekend", you can see her watching "Misty the Homesick Snorky Puff 3". So apparently, she likes baby movies.
- Megan's last name, "Uno", is Spanish for the word "one", and one is an odd number before number two.
- Megan's last name is also the last name of Nigel Uno a.k.a. Numbuh 1 from "Codename: Kids Next Door".