Jack Doyle (December 27, 1877 – January 30, 1944) was an American railroad engineer, saloon owner, boxing promoter, and oil-industry investor.

In the 1910s he ran what was called the "longest bar in the world" in Vernon, California, United States.

He retired from fight promotion by 1932 and successfully transitioned to oil drilling at Signal Hill.

[4] His brother Thomas Doyle served in the California State Assembly.

[2] Doyle died in Santa Monica, California, in 1944 at the age of 66.