Hugh Brannum (January 5, 1910 – April 19, 1987) was an American vocalist, arranger, composer, and actor known for his role as Mr. Green Jeans on the children's television show Captain Kangaroo.

[3][4] After the war, he joined the Four Squires, and later moved to Fred Waring and His Pennsylvanians; Waring's group had a regular radio show on NBC, where Brannum met fellow Marine Bob Keeshan, who was working at the network, and who later hired Brannum for Captain Kangaroo.

Before his time on Captain Kangaroo, Brannum hosted a local children's TV series called Uncle Lumpy's Cabin, seen weekday afternoons at 5 on WJZ-TV, (now WABC-TV) in New York City during the 1951 season.

Aside from Mr. Green Jeans, Brannum played a number of characters on Captain Kangaroo from 1955 to 1984, including the Professor, Greeno the Clown, the New Old Folk Singer, and Mr. Bainter the Painter.

His role as Mr. Green Jeans was partly based on stories about a farm kid named "Little Orley" that he told with the Fred Waring orchestra, on the radio and on 78-rpm records under the pseudonym "Uncle Lumpy".