Republican
The 1957 New Jersey Senate elections were held on November 5.
The elections coincided with the re-election of Governor Robert Meyner. Ten of New Jersey's 21 counties elected Senators. Democrats gained one seat in Passaic County, where Anthony J. Grossi unseated incumbent Republican Frank W. Shershin.
Seats where the margin of victory was under 10%:
Seats where the margin of victory was 10% or greater; and the seat flipped party control:
State Senator James F. Murray Jr. announced here today after an hour-long talk with Gov. Robert B. Meyner that he would not seek re-election to the Senate.