American television producer and entertainer best known for his role as Captain Kangaroo on the children's program of the same name (1955–84).

When Keeshan was a senior in high school, he landed a job as a page at NBC in New York City. After high school he served in the Marines. In 1946 he returned to New York and to his job at NBC and also attended Fordham University. His desk at NBC was next to Buffalo Bob Smith's office, and Keeshan soon was helping Buffalo Bob with a Saturday morning children's radio show. The next year, when Buffalo Bob starred in an afternoon show, he featured a puppet—Howdy Doody—and Keeshan was invited to join the cast. On Jan. 3, 1948, he debuted as Clarabell the Clown on what later became The Howdy Doody Show, and by 1950 the show had moved to television and was highly popular. Keeshan's next stint was as Corny the Clown on ABC's Time for Fun, and he then performed on that network's Tinker's Workshop.

Captain Kangaroo—given that name because in the show's early years Keeshan wore an oversize coat with large pockets reminiscent of kangaroo pouches—began on Oct. 3, 1955. The walrus-mustached Captain—with such friends as Mr. Green Jeans, Bunny Rabbit, Dancing Bear, and Mr. Moose—brought education disguised as entertainment to his audiences and endeared himself to generations of young viewers. The show aired regularly on CBS until 1984, after which it ran as specials on CBS and on public television. It won six Emmy Awards and three Peabody Awards.

Keeshan also wrote several books—including his 1995 memoir Good Morning, Captain—and involved himself in a number of civic causes, especially those concerning children.