Referring to a small swamp located within the southern portion of the suburb, the name Gwelup has been derived from the Aboriginal word "Gwelgannow" meaning "to shift position."
The land near the lake was first granted to Thomas Mews in 1831, passing through several owners before being acquired by Henry Bull, of Sydney, in 1891. Bull subdivided Gwelup in 1898 and 1899 but development was relatively slow and the land was mainly used for market gardens in the early years.
In addition to Lake Gwelup itself, another significant landmark is the Careniup Wetlands Reserve, first recorded as part of a survey in 1844. The name Karrinyup appears to have been derived from this swamp, located on the northern boundary of Gwelup.