The Alvis Pelides was an unflown British air-cooled radial aero engine first developed in 1936.

[1] The Pelides was the first aero engine of Alvis design; the company had previously only built the French Gnome-Rhône Mistral Major under license.

[2] With the two companies working closely together the 14 cylinder radial layout of this engine retained metric dimensions but substituted metric screw threads with British fasteners such as BSF and Whitworth.

The Pelides passed a 50-hour Air Ministry type test in 1937 where it produced 1,065 hp (794 kW) but no aircraft application was found and only 15 engines were built.

The onset of the Second World War caused the abandonment of any further development of the Pelides and its related designs.