Rainbow Mars is a 1999 science fiction short story collection by American writer Larry Niven.

It contains six stories of Hanville Svetz, five previously published and the longest, "Rainbow Mars", written for the collection.

In order to maintain the interest of the Secretary, different factions in the capitol use their advanced science to amuse him.

Svetz's section uses time travel in an attempt to bring back long extinct animals from Earth's past.

Unbeknownst to Svetz and his team, they are actually travelling back into fictional pasts, and returning with mythical creatures.