Lassie is an American television series that follows the adventures of a female rough collie named Lassie and her companions, human and animal. The show was the creation of producer Robert Maxwell and animal trainer Rudd Weatherwax and was televised from Sunday September 12, 1954, to Sunday March 24, 1973. One of the longest running dramatic series on television, the show ran for seventeen seasons on CBS before entering first-run syndication for its final two seasons.

The show's first ten seasons follow Lassie's adventures in a small farming community. Seven-year-old Timmy Martin and his adoptive parents do not become Lassie's owners until the fourth season. When Lassie's exploits on the farm end in the eleventh season, she finds new adventures in the wilderness with a succession of United States Forestry Service workers. After traveling without human leads for a year, Lassie finally settles at a children's home for her final two syndicated seasons.

Lassie, Timmy, and Timmy's mother appear in "Mr. Griffin Goes to Washington", in a demonstration of subliminal advertising by Jerry of the El Dorado Cigarette Company. Timmy and his mother are both voiced by Alex Borstein.

Peter tries to figure out how to handle giving Brian a suppository in "Once Bitten" by watching an old episode of Lassie in which Lassie tricks Timmy into giving her a suppository as a prank.

Stewie tells Brian that Rupert used to call him names in "Dog Bites Bear", including "fat Lassie."

Among the television shows featured in the background during Peter's introduction to ""Family Guy" Through the Years" is an image of Lassie.