Pat Olivieri (died 1970) was an Italian-American restaurateur. He is credited, along with his brother, Harry Olivieri, as the 1930 co-creator of the cheesesteak. The brothers opened Pat's King of Steaks in 1930, one of the best known purveyors of steak sandwiches in Philadelphia.
In 1930, Pat opened a hot dog stall with his younger brother Harry Olivieri at the corners of 9th Street, Wharton and Passyunk Avenues. The brothers ran the restaurant while holding down other jobs; Pat made sleds, while Harry worked as a carpenter.
In 1930, as the family relates the story, the brothers invented the steak sandwich. Pat gave the first half of one to a cab driver for free.
By 1933, they rented space to open a restaurant at the same spot that they had their stand. The two brothers worked at the restaurant for 15 to 18 hours a day for the next few decades while the restaurant was open 24 hours a day.
In 1965, Pat retired to southern California after a family dispute.
Pat died in 1970. His son Herbert Olivieri disputed ownership of the business with Harry Olivieri and his children. Harry's grandson Frank Jr. now runs the business.
- "Harry Olivieri - Co-creator of the Philly Cheesesteak". The Guardian. 2006-08-21. Retrieved 2015-12-01.
-  Pat's King of Steaks official website.
- "Harry Olivieri, 90, Co-inventor Of Cheese Steak in Philadelphia". The New York Times. 2006-08-22. Retrieved 2015-12-01.