Pascoe St Leger Grenfell (5 November 1798 — 27 March 1879) was a British businessman who was a key backer of the South Australian Company.

On the abolition of slavery by Britain in 1833, Grenfell applied for compensation for the 347 slaves he owned in Jamaica.

Grenfell with South Australia Company Director Raikes Currie, William Wolryche-Whitmore and Reverend Sir Henry Robert Dukinfield were key committee members of the Society for the Propagation of the Gospel in Foreign Parts (SPG) and were all involved with the establishment of South Australia as a free colony.

Colonel William Light, the Surveyor General of the new colony and the City of Adelaide, had authority to select land for the South Australian Church Society.

[9] The entire donation had an estimated value of 70 shillings and made him the largest private contributor to the venture.