Usermontu was a vizier

Vizier (Ancient Egypt)

The vizier was the highest official in Ancient Egypt to serve the king, or pharaoh during the Old, Middle, and New Kingdoms. Vizier is the generally accepted rendering of ancient Egyptian tjati, tjaty etc, among Egyptologists...

 to Tutankhamen and likely of Horemheb

Horemheb

Horemheb was the last Pharaoh of the 18th Dynasty from either 1319 BC to late 1292 BC, or 1306 to late 1292 BC although he was not related to the preceding royal family and is believed to have been of common birth.Before he became pharaoh, Horemheb was the commander in chief...

.

Usermontu is depicted in the tomb of Khons, called To (TT 31). In the hall Usermontu and his brother Huy, who was a prophet of Montu are shown offering to the barque of Montu. Usermontu is said to be born of Maia. A statue from a private collection gives the name of his father as Nebmehyt.

A second individual by the name of Usermontu is mentioned in the tomb, but this individual is the son of Khonsu. This younger Usermontu is a High Priest of Sobek.

The Vizier Usermontu is also depicted in the tomb of the High Priest of Sobek, Hatiay (TT 324). Usermontu is shown seated at a banquet with vizier Nebamun(?).

A stela from Usermontu was found in Armant. The text includes a hymn to Montu.