Durham paceman Onions won the last of his nine Test caps against the West Indies at Edgbaston last year. He was joined in the squad by Yorkshire seam-bowling all-rounder Tim Bresnan, who missed the recent home series win over Australia while he recovered from elbow surgery.
Also in the squad were pace trio James Anderson, Stuart Broad and Steven Finn.
Broad missed England's warm-up win over Essex with a shoulder injury, a match where key off-spinner Graeme Swann was struck a painful blow on the right arm having had surgery on his right elbow earlier this year. But both bowlers were passed fit.
Somerset opener Compton, grandson of England great Denis, scored back-to-back hundreds in New Zealand earlier this year but was omitted after a poor return series against the Kiwis that saw him manage just 39 runs in four innings.
Meanwhile star batsman Kevin Pietersen returned to the Test squad for the first time since March following a knee injury.