| Mosher Joseph Blumenfeld | |
| Office: | Senior Judge of the United States District Court for the District of Connecticut |
| Term Start: | January 20, 1977 |
| Term End: | November 5, 1988 |
| Office1: | Chief Judge of the United States District Court for the District of Connecticut |
| Term Start1: | 1971 |
| Term End1: | 1974 |
| Predecessor1: | William H. Timbers |
| Successor1: | T. Emmet Clarie |
| Office2: | Judge of the United States District Court for the District of Connecticut |
| Term Start2: | August 15, 1961 |
| Term End2: | January 20, 1977 |
| Appointer2: | John F. Kennedy |
| Predecessor2: | Seat established by 75 Stat. 80 |
| Successor2: | Ellen Bree Burns |
| Birth Date: | 23 March 1904 |
| Birth Place: | Saint Paul, Minnesota |
| Death Place: | Hartford, Connecticut |
| Education: | University of Minnesota (B.A.) Harvard Law School (LL.B.) |
Mosher Joseph Blumenfeld (March 23, 1904 – November 5, 1988) was a United States district judge of the United States District Court for the District of Connecticut.
Born on March 23, 1904, in Saint Paul, Minnesota, Blumenfeld received at Bachelor of Arts degree in 1925 from the University of Minnesota and a Bachelor of Laws in 1928 from Harvard Law School. He worked in private practice in Hartford, Connecticut, from 1928 to 1961. He was a special assistant to the United States Attorney for the District of Connecticut from 1942 to 1946.
Blumenfeld was nominated by President John F. Kennedy on August 7, 1961, to the United States District Court for the District of Connecticut to a new seat authorized by 75 Stat. 80. He was confirmed by the United States Senate on August 15, 1961, and received his commission on August 15, 1961. He served as chief judge from 1971 to 1974. He assumed senior status on January 20, 1977. His service terminated on November 5, 1988, when he died in Hartford.