The 1904 Illinois gubernatorial election was held on November 8, 1904.
Incumbent Republican Governor Richard Yates Jr. was denied renomination by his party.
Republican nominee Charles S. Deneen defeated Democratic nominee Lawrence B. Stringer with 59.09% of the vote.
The Democratic state convention was held on June 15, 1904, at the State Armory in Springfield.
The Republican state convention was held from May 12 to 20 and, following a recess, from May 31 to June 3, 1904, at the State Armory in Springfield.
The results of the balloting were as follows (fractions ignored until 39th ballot):
Following the 79th ballot, Lowden moved that the nomination of Deneen be made unanimous, which was carried viva voce.