Challenge to Lassie is an American drama directed by Richard Thorpe in Technicolor and released October 31, 1949, by MGM Studios. It was the fifth feature film starring the original Lassie, a collie named Pal, and the fourth and final Lassie film starring Donald Crisp.

The movie is based on Eleanor Stackhouse Atkinson's 1912 novel Greyfriars Bobby which in turn is based on the supposedly true story of Greyfriars Bobby. Twelve years after starring in Challenge to Lassie, Crisp would star in another movie based on the novel and produced by Walt Disney titled, Greyfriars Bobby.

Set in Scotland in 1860, the film tells the story of a rough collie named Lassie whose master, Jock Gray, is killed by robbers in Edinburgh. After his death, the dog keeps a constant vigil beside her master's grave in Greyfriars Kirkyard, which is in violation of the local dog laws. In the original novel, the title dog was a Skye Terrier named Bobby, and his owner dies from pneumonia.