38 Leda is a large, dark main-belt asteroid that was discovered by French astronomer J. Chacornac on January 12, 1856, and named after Leda, the mother of Helen of Troy in Greek mythology.

[4] The spectra of the asteroid displays evidence of aqueous alteration.

[6] During 2002, 38 Leda was observed by radar from the Arecibo Observatory.

The return signal matched an effective diameter of 116 ± 13 km.

[7][8] Based upon a light curve that was generated from photometric observations of this asteroid at Pulkovo Observatory, it has a rotation period of 12.834 ± 0.001 hours and varies in brightness by 0.15 ± 0.01 in magnitude.