Steven J. Ostro is an astronomer at the Jet Propulsion Laboratory of the National Aeronautics and Space Administration. Ostro was part of the team of astronomers that discovered asteroid 1998 KY₂₆ in 1998.

From August 19 to 22 of 1989, Ostro and Scott Hudson observed 4769 Castalia from the Arecibo Observatory. The data collected by them allowed astronomers to produce the first direct image of an asteroid.

In March of 1996 Ostro and Lance Benner led a process at the Goldstone Observatory that produced sufficient data to image 2063 Bacchus.

The asteroid 3169 Ostro is named in his honour.