Leni Loud is one of Lincoln's ten sisters and Lori's former roommate who is one of the main characters in 1st-4th season and the deuteragonist in the fifth season on The Loud House. She is the second-oldest child in the Loud family, at 16 years old in seasons 1 to 4, and 17 years old in season 5. She is the kindest, but also the least brightest of the eleven siblings. In spite of her fulfilling the "dumb blonde" stereotype, she is quite talented in fashion designing, wood carving, and lock-picking. She now works as an employee of Reininger's and the current oldest sibling of the house in the fifth season when Lori moving out to attend Fairway University.
Various examples of Leni's simple-mindedness are expressed throughout the series. In "Linc or Swim", she does not know the rules of the game, "Marco Polo", much to Luan's annoyance. In "Project Loud House", she is shown to be unable to walk and chew bubble gum at the same time. In "Changing the Baby", she gets stuck in Lily's crib and thinks that it's a baby prison. When she's being interrogated by Lincoln and Lucy in "Sleuth or Consequences", she thinks they're interviewing her, and states that her favorite color is zebra.
Despite being ditzy, shy, and scatter-brained, Leni's shown to be skilled at fashion designing, wood carving, singing, lock-picking, and making smoothies, which demonstrates that while she may not be very bright, she is creative and artistically inclined. She is also the kindest and sweetest out of the bunch and gets along well with all of her siblings. She also has a crush on Chaz, a fat but kind-hearted boy who is one of Lori's friends and shares her interest in fashion.
Leni's willingness to help others, in fact, is what gets her a job at the clothing store Reininger's in the episode "Shop Girl". In "Crimes of Fashion", she was wrongly fired from her job by Ms. Carmichael after being mistakenly accused of stealing several scarfs from her department. After Lincoln and Clyde found out that Ms. Carmichael's son did it (having used said scarves as capes), she was re-hired by Ms. Carmichael, who apologized for the accusation. Leni would later be made temporary manager of Reininger's in "Leader of the Rack" and is named employee of the month in "The Boss Maybe".
Leni suffers from arachnophobia, as seen in "Left in the Dark", "No Guts, No Glori" and "Future Tense". This phobia is most prominent in "Along Came a Sister", where Lincoln brings his class's pet spider, Frances, home. When Leni first sees Frances, she panics and attempts to kill her with bug spray. Later on, it is revealed that Frances is still alive, and Dad – who also exhibits arachnophobia – hires an exterminator to dispose of her. Leni faces her fear and stops the exterminator, in order to save Lincoln's reputation – once again – showing that she does have a big heart.
Leni has also shown that she can be irresponsible, as shown in the episode "Cover Girls", where she agreed to cover for Luna, Luan, Lynn, Lucy, Lola, and Lana, only to then pass the task onto Lincoln. However, Leni is shown to be very compassionate, as she was the only one of her siblings to prioritize helping her family get better, as opposed to getting away when the Loud family caught the flu in "One Flu Over the Loud House". In addition, in "No Spoilers", it is shown she is the only person in the family considerate enough in the family to be able to make the perfect surprise party because she pays attention to what people like (excluding the surprise part since she always spoils the surprise because can't keep a secret).
As of the fifth-season, Leni is now the oldest sibling living in the house, while her older sister and former roommate Lori is attending college at Fairway University (aside from visiting on weekends).
Episodes focusing on Leni
- "Driving Miss Hazy"
- "Along Came a Sister"
- "Change of Heart"
- "No Spoilers"
- "Fandom Pains"
- "Shop Girl"
- "Crimes of Fashion"
- "Sitting Bull"
- "Everybody Loves Leni"
- "Leader of the Rack"
- "Don't You Fore-get About Me"
- "Snoop's On"
- "The Boss Maybe"
- "Undercover Mom"
- "Grub Snub"