| Bernard Martin Decker | |
| Office: | Senior Judge of the United States District Court for the Northern District of Illinois |
| Term Start: | April 2, 1980 |
| Term End: | November 3, 1993 |
| Office1: | Judge of the United States District Court for the Northern District of Illinois |
| Term Start1: | December 12, 1962 |
| Term End1: | April 2, 1980 |
| Appointer1: | John F. Kennedy |
| Predecessor1: | Seat established by 75 Stat. 80 |
| Successor1: | John Albert Nordberg |
| Birth Name: | Bernard Martin Decker |
| Birth Date: | 2 April 1904 |
| Birth Place: | Highland Park, Illinois |
| Death Place: | Chicago, Illinois |
| Education: | University of Illinois at Urbana–Champaign (A.B.) Harvard Law School (LL.B.) |
Bernard Martin Decker (April 2, 1904 – November 3, 1993) was a United States district judge of the United States District Court for the Northern District of Illinois.
Born in Highland Park, Illinois, Decker received an Artium Baccalaureus degree from the University of Illinois at Urbana–Champaign in 1926 and a Bachelor of Laws from Harvard Law School in 1929. He was in private practice in Waukegan, Illinois from 1929 to 1951. He was a law clerk to a Judge of the Illinois Appellate Court from 1944 to 1948. He was a Judge of the Illinois Circuit Court from 1951 to 1962.
Decker received a recess appointment from President John F. Kennedy on December 12, 1962, to the United States District Court for the Northern District of Illinois, to a new seat authorized by 75 Stat. 80. He was nominated to the same position by President Kennedy on January 15, 1963. He was confirmed by the United States Senate on March 28, 1963, and received his commission on April 2, 1963. He assumed senior status on April 2, 1980. His service terminated on November 3, 1993, due to his death in Chicago, Illinois.