[1] Mishigiin Sonompil was born in Tes sum, Uvs Aimag (province).

Sonompil's political career began when his Parliamentary Member brother Mishigiin Chimedtseren died in a deltaplane accident in 1997.

He ran as an MP candidate from the Democratic Union Coalition, to fill in his died brother's position, but he was unsuccessful in both the 1997 and 2000 elections.

However, in January 2006 he voted with the former communist MPRP members against the coalition government of Tsakhiagiin Elbegdorj.

In the new government under Miyeegombyn Enkhbold of MPRP, Mishigiin Sonompil was awarded the role of Minister of Defense.