William Thompson Walters was an American businessman and art collector, whose collection formed the basis of the Walters Art Museum.

Walters Art Museum is a public art museum located in the Mount Vernon section of Baltimore, Maryland. Founded and opened in 1934, it holds collections from the mid-19th century that were amassed substantially by major American art and sculpture collectors, including William Thompson Walters and his son Henry Walters. William Walters began collecting when he moved to Paris as a nominal Confederate loyalist at the outbreak of the American Civil War in 1861, and Henry Walters refined the collection and made arrangements for the construction what ultimately was Walters Art Museum.