Encyclopedia Brown is a series of books featuring the adventures of boy detective Leroy Brown, nicknamed "Encyclopedia" for his intelligence and range of knowledge. The series of 29 children's novels was written (one co-written) by Donald J. Sobol, with the first book published in 1963 and the last published posthumously in 2012. In addition to the main books, the Encyclopedia Brown series has spawned a comic strip, a TV series, and compilation books of puzzles and games.

Sobol's first Encyclopedia Brown book was written in two weeks; subsequent books took about six months to write. Its main publisher was Bantam Skylark.