Sampson Flat is a locality northeast of Adelaide, South Australia in the City of Playford. It used to be known as Sampson's Flat. The area drains to the west into the Little Para Reservoir. It is a mixture of open pasture with scattered trees, and denser scrub on the higher eastern side. Sampson Flat was possibly named after John H. Sampson, who arrived in South Australia in 1849 and resided at One Tree Hill.