The Great Gildersleeve is a radio situation comedy broadcast from August 31, 1941, to March 21, 1957. Initially written by Leonard Lewis Levinson, it was one of broadcast history's earliest spin-off programs. The series was built around the character Throckmorton P. Gildersleeve, a regular element of the radio situation comedy Fibber McGee and Molly. The character was introduced in the October 3, 1939 episode (number 216) of that series. The Great Gildersleeve enjoyed its greatest popularity in the 1940s. Actor Harold Peary played the character during its transition from the parent show into the spinoff and later in four feature films released at the height of the show's popularity.

In Fibber McGee and Molly, Peary's Gildersleeve had been a pompous windbag and nemesis of Fibber McGee. "You're a haa-aa-aa-aard man, McGee!" became a Gildersleeve catchphrase. The character went by several aliases on Fibber McGee and Molly; his middle name was revealed to be "Philharmonic" in "Gildersleeve's Diary" episode on October 22, 1940.

"Gildy" grew so popular that Kraft Foods-promoting its Parkay margarine sponsored a new series featuring Peary's somewhat mellowed and always befuddled Gildersleeve as the head of his own family.

The Great Gildersleeve premiered on NBC on August 31, 1941. It moves the title character from the McGees' Wistful Vista to Summerfield, where Gildersleeve oversees his late brother-in-law's estate and rears his orphaned niece and nephew, Marjorie and Leroy Forrester. The household also includes a cook named Birdie. While Gildersleeve had occasionally mentioned his (unseen) wife in some Fibber episodes, in his own series he is a confirmed bachelor. At the outset of the series, Gildersleeve administers a girdle manufacturing company ("If you want a better corset, of course, it's a Gildersleeve"); later and during the remainder of the show he serves as Summerfield's water commissioner.