The existence of quasars in the early Universe and their associated supermassive black holes with masses of around 1 billion solar masses has been used to argue that supermassive stars are required to seed these black holes. While the existence of a first generation of stars (which must be metalfree) is not disputed – their masses are expected to range from around 10 solar masses up to 1000 solar masses at most. There are strong theoretical reasons why these masses are too small to provide the seeds for the SMBHs observed at the same epoch. Hence, a strong case for a heavy seed – a supermassive star is made. In this talk I will examine what we think are the conditions required to form these objects and I will show some of the latest work which explores this scenario.