Sidney Breese (September 7, 1800-June 27, 1878) was a U.S. Senator from Illinois.
Breese was born in Whitesboro, New York and attended Hamilton College and Union College. Upon graduating in 1818, he moved to Illinois and was admitted to the bar in 1820. After serving as a militia officer in the Black Hawk War he was made a circuit court judge and thereafter appointed to the Illinois Supreme Court. In 1843, he was elected to the U.S. Senate but failed to gain a renomination in 1849 (in those years senators were elected by state legislatures). He nontheless continued his career in state politics and the judiciary including three terms as state Chief Justice.
Preceded by: Richard M. Young Class 3 U.S. Senator from Illinois 18343-1849 Succeeded by: James Shields