Mathias Bonsach Krogh Nannestad (1815–1878) was a Norwegian civil servant and politician.
He served as the County Governor of both Finnmark and Tromsø counties from 1858 until 1866.
In 1866, the position was split with Jens Holmboe taking over in Finnmark and Nannestad remaining as the County Governor of Tromsø county until his retirement in 1869.