Castelo Rá-Tim-Bum (Portuguese pronunciation: [kasˈtɛlu ʁatʃĩˈbũ], lit. "Ra-Tim-Bum Castle") is a Brazilian children's program produced and broadcast by TV Cultura and the Network Service of Television. Targeted toward children and youth, it follows an educational entertainment model, being composed of several segments targeting specific knowledge areas, such as science and history. The program premiered on May 9, 1994, and stopped production in 1997. Partially inspired by the educational program Rá-Tim-Bum, it gave rise to a television franchise, which is part of Island Rá-Tim-Bum. Castelo Rá-Tim-Bum is a creation of the playwright Flavio de Souza and director Cao Hamburger, with scripts Jacob Dionisio (Tacus), Cláudia Dalla Verde, Anna Muylaert, among others.

Because of its educational nature, the production was part of a partnership between Fiesp and TV Cultura, such as other educational programs for children that the station aired. Fiesp, Sesi and Senai were all educational institutions that appeared in its credits. Although the series was targeted towards children from 3 to 8 years old, it actually had an audience of 3 to 16 year olds.