Thimble Theater later became Popeye after the sailor character who became the most popular member of the comic strip's cast. Olive Oyle was a character in the strip for years before the first appearance of Popeye.
The version of Olive Oyl most widely familiar is the version from the movie animated cartoons, first created by Fleischer Studios, and then produced by Paramount Pictures. In the films and later television cartoons, Olive Oyl is Popeye's girlfriend. She constantly gets kidnapped by Bluto (aka Brutus) who is Popeye's rival for her affections but Popeye always rescues her. She has a baby named Sweet Pea; it is not made clear if Sweet Pea is Olive Oyl's own son or an adopted foundling. It's unknown whether she is divorced or widowed.
Olive Oyl is named after olive oil, a common cooking ingredient in Italian and Mediterranean dishes. Segar's newspaper strips also featured a number of her relatives named after other oils, including her brother Castor Oyl and their mother Nana Oyl (after "Banana Oil", a slang phrase of the time with roughly the same meaning as "bullshit").