The 47-year-old was one of 12 players to clinch a spot in the second Major of the season at Merion Golf Club in Pennsylvania from June 13-16 after rounds of 68 and 73 gave him a three-under total of 141.
"I'm very pleased to be going to Merion," double U.S. Masters champion Olazabal told reporters. "It's not very often you are involved in a six-man playoff so I'm delighted to get through."
The Spaniard and British pair David Howell and John Parry all advanced with birdies at the first extra hole.
Argentine Estanislao Goya and Briton Chris Doak also qualified, leaving Swede Rikard Karlberg as the only one to miss out from the playoff.
Britain's Simon Khan, beaten by Italian Matteo Manassero in a playoff in the PGA Championship at Wentworth on Sunday, was the leading qualifier on seven-under 137.
British pair Paul Casey and Eddie Pepperell, South African Jaco van Zyl, Morten Madsen of Denmark, Swede Peter Hedblom and Australian Marcus Fraser will also be competing at Merion.
- Sports & Recreation
- Merion Golf Club
- David Howell