271 Penthesilea is a mid-sized main belt asteroid that was discovered by Viktor Knorre on 13 October 1887 in Berlin.

The asteroid was named after Penthesilea, the mythical Greek queen of the Amazons.

[4] Photometric observations of this asteroid were made in early 2009 at the Organ Mesa Observatory in Las Cruces, New Mexico.

The resulting light curve shows a synodic rotation period of 18.787 ± 0.001 hours with a brightness variation of 0.32 ± 0.04 in magnitude.

This article about an asteroid native to the asteroid belt is a stub.