Johannes "Hannes" Jacobus Gerhardu Dreyer (born 13 January 1985) is a South African sprinter who specializes in the 100 metres.

[1] Dreyer represented South Africa at the 2008 Summer Olympics in Beijing.

He competed at the 4x100 metres relay together with Leigh Julius, Ishmael Kumbane and Thuso Mpuang.

In their qualification heat they did not finish due to a mistake in the baton exchange and they were eliminated.

This biographical article relating to South African athletics is a stub.