Fleet of Worlds is a science fiction novel by American writers Larry Niven and Edward M. Lerner, part of Niven's Known Space series.

Fleet of Worlds can also refer to the series consisting of this book and its four sequels.

The novel, co-written by Niven and Edward M. Lerner, was released in 2007 and nominated for a Prometheus Award.

The novel concerns the liberation of New Terra from the Concordance of the Pierson's Puppeteers.

The Fleet of Worlds series consists of five books by the same authors: The first four novels are prequels to Ringworld.