Additionally, Republicans won all seats up for election on the Board of Trustees of the University of Illinois.

In October, before the general election, his death in office made John Henry Stelle assume the governorship.

John Henry Stelle (before primary)Democratic PartyVacant (before general election) Hugh W. Cross Republican Incumbent lieutenant governor John Henry Stelle, a Democrat, did not seek reelection to a second term, instead opting to run for governor.

Justus L. Johnson won the Republican primary, defeating businessman Richard Yates Rowe and Illinois state senator Arthur J. Bidwill.

Incumbent Edward J. Barrett narrowly lost renomination to U.S. congressman and former Illinois state treasurer John C. Martin.

[1][7] New Republican members John R. Fornof and Park Livingston were elected to the board.

[1][7] Incumbent first-term Democrat Marie Coyle Plumb lost reelection.

[1][7] Republican Chester R. Davis was elected, defeating incumbent Kenny E. Williamson (who had been appointed to hold the seat after the death of Moschel).

[1][7] On June 3, 1940, an election was held for judges of the Superior Court of Cook County.

On November 5, 1940, an election was held to fill a vacancy on the Eighth Judicial Circuit.