Young replaces Rick Peterson, who took the same post with the New York Mets.
Young, 43, spent last season as pitching coach for Oakland's Triple-A affiliate at Sacramento, where he worked with top prospects Rich Harden, Justin Duchscherer, Mike Wood, and Chad Harville. The River Cats ranked fourth in the Pacific Coast League with a 3.90 ERA.
"I don't think there have to be a lot of big adjustments with the Big Three, we'll just let them find their way and help them along," said Manager Ken Macha, referring to Oakland stalwarts Tim Hudson, Mark Mulder, and Barry Zito, all of whom have worked with Young in varying degrees.
A 1981 fourth-round pick of the A's, the southpaw was 69-53 with a 4.31 ERA in 251 games with Oakland, Kansas City, and the New York Yankees with three career shutouts and a pair of one-hitters.