176 Iduna is a large main-belt asteroid that was discovered by German-American astronomer Christian Heinrich Friedrich Peters on October 14, 1877, in Clinton, New York.

It is named after Sällskapet Idun, a club in Stockholm that hosted an astronomical conference; Idun (Iðunn, Iduna) is also a Norse goddess.

An occultation of a star by Iduna was observed from Mexico on January 17, 1998.

Photometric observations of this asteroid at the Romer Observatory in Aarhus, Denmark during 1996 gave a light curve with a period of 11.289 ± 0.006 hours and a brightness variation of 0.35 in magnitude.

[2] A 2008 study at the Palmer Divide Observatory in Colorado Springs, Colorado gave a period of 11.309 ± 0.005 hours, confirming the 1996 result.