Geoffrey Fantham Sim QSO (2 April 1911 – 27 March 2002) was a New Zealand politician of the National Party.
He received his education at Morrinsville, Pukekohe High School, and King's College.
After school, he was a farmer at Waimārama, was involved in felling bush, was a driver in the Onewhero and Thames region, became head shepherd at Crossland Station near Kaipara Harbour, before working as a stock agent in Waiuku.
The National Party nominated him in the Rotorua electorate for the 1943 election, where he was successful.
[4] In the 1963 election, he successfully contested the Piako electorate, and retired at the end of the next parliamentary term in 1966.