Lucas is a 1986 American teen tragicomedy film directed by David Seltzer and starring Corey Haim, Kerri Green, Charlie Sheen and Courtney Thorne-Smith. The film was Winona Ryder's screen debut.

Lucas Bly (Haim) is an extremely intelligent and nerdy 14-year-old high school student. He soon becomes acquainted with Maggie (Green), an attractive older girl who had just moved to town. After meeting Lucas on one of his entomological quests, Maggie befriends him, spending time with him during the remainder of the summer until school begins. Lucas, who finds himself a frequent victim of bullying and teasing, has a protector of sorts, Cappie Roew (Sheen), a fellow student and football player; Cappie was once one of Lucas' tormentors, until Cappie contracted hepatitis and Lucas brought him his homework every day, ensuring that Cappie didn't fail and have to repeat a year of school. Even though Lucas deems it beneath her, Maggie becomes a cheerleader for the football team in order to get closer to Cappie, on whom she has a growing crush. Angered and offended by Maggie continuing to ignore him, Lucas begins to irritate Maggie, continuing to castigate her cheerleading as "superficial" and making the incorrect assumption that she will be his date to an upcoming school dance. Maggie complains to Lucas that she's interested in things besides just hanging out with him all the time, and Lucas' unrequited affection for her continues to upset him.