| Ann D. Montgomery | |
| Office: | Senior Judge of the United States District Court for the District of Minnesota |
| Term Start: | May 31, 2016 |
| Office1: | Judge of the United States District Court for the District of Minnesota |
| Term Start1: | August 6, 1996 |
| Term End1: | May 31, 2016 |
| Appointer1: | Bill Clinton |
| Predecessor1: | Diana E. Murphy |
| Successor1: | Nancy E. Brasel |
| Office2: | Magistrate Judge of the United States District Court for the District of Minnesota |
| Term Start2: | 1994 |
| Term End2: | 1996 |
| Birth Name: | Ann Day Olson |
| Birth Date: | 9 May 1949 |
| Birth Place: | Litchfield, Minnesota, U.S. |
| Education: | University of Kansas (BS) University of Minnesota (JD) |
Ann Day Montgomery (née Olson; born May 9, 1949)[1] is a senior United States district judge of the United States District Court for the District of Minnesota.
Montgomery was born in Litchfield, Minnesota. She received a Bachelor of Science degree from the University of Kansas in 1971 and a Juris Doctor from the University of Minnesota Law School in 1974. She was a law clerk to Gerard D. Reilly and Hubert Pair, both of the District of Columbia Court of Appeals from 1974 to 1975. She was an Assistant United States Attorney of the District of Minnesota from 1976 to 1983. She was a judge on the Hennepin County Municipal Court, Minnesota from 1983 to 1985, and of the county's District Court in Minneapolis from 1985 to 1994.
Montgomery became a United States magistrate judge of the United States District Court for the District of Minnesota in 1994.
On November 27, 1995, Montgomery was nominated by President Bill Clinton to a seat on the United States District Court for the District of Minnesota vacated by Judge Diana E. Murphy. Montgomery was confirmed by the United States Senate on August 2, 1996, and received her commission on August 6, 1996. She assumed senior status on May 31, 2016.