Stephanie is a fictional character from the children's television series LazyTown, created by Magnús Scheving. She is portrayed as an energetic girl who encourages the residents of LazyTown to be more physically active and to adopt healthier habits. In the series, she comes to LazyTown to visit her uncle, Milford Meanswell, the town's mayor, and befriends the local children. She is known for her pink hair, which leads the puppet character Trixie to nickname her "Pinky".

The character originated in the Icelandic stage play Áfram Latibær! (1996), in which she appeared under the name Solla Stirða. For the television adaptation, the character was reworked into Stephanie. In the Icelandic dub of the television series, she was voiced by Ólöf Kristín Þorsteinsdóttir.

Stephanie was portrayed by Julianna Rose Mauriello in the first two seasons of LazyTown and by Chloe Lang in the third and fourth seasons. In earlier stage productions, she was played by Selma Björnsdóttir and Linda Ásgeirsdóttir, and she was also portrayed by Kimberly Pena in LazyTown Live! The Pirate Adventure.

Stephanie was depicted as being an athletic, sweet, shy, sassy, caring, optimistic, and smart 8-year-old girl. Surprised by the inactivity of the residents of LazyTown, she cheerfully encourages them to participate in more active, energetic hobbies or pastimes such as sports, games, and much more when they are downhearted when the temptations of candy or video games overcome her prodding. Despite this, Stephanie is characterized by her optimism and self-confidence, which she proudly promotes and shares with her peers in encouragement against all odds or challenges, always victoriously triumphing over any obstacles or antagonists by the conclusion of an episode.

Stephanie's attempts are often nearly thwarted by Robbie Rotten, but his plans are never foolproof and always end with Stephanie winning.

Stephanie was originally created by Magnús Scheving for the stage play Áfram Latibær as "Solla Stirða" ("Solla Stiff"), a girl with stiff joints who dreamt of becoming a dancer. Solla also appeared in the sequel to the stage play, Glanni Glæpur í Latabæ. She was played by Selma Björnsdóttir and Linda Ásgeirsdóttir, respectively.

Magnús Scheving reworked Solla into Stephanie for the LazyTown television show. Shelby Young was originally pegged to play Stephanie in 2003, and filmed one unaired pilot before departing due to union issues.

Ultimately, Julianna Rose Mauriello was chosen to play Stephanie, and played her for the first two seasons and LazyTown Extra before departing due to aging out of the role.