Mary Theresa O'Connor (born June 19, 1955 in Hokitika, West Coast) is a retired female long-distance runner from New Zealand. She competed for her native country at the 1984 Summer Olympics in Los Angeles, California. There she ended up in 27th place in the women's marathon. O'Connor set her personal best in the classic distance (2:28.20) in 1983.
| Year | Competition | Venue | Position | Notes |
|---|---|---|---|---|
| Representing New Zealand | ||||
| 1983 | World Championships | Helsinki, Finland | 34th | Marathon |
| 1984 | Olympic Games | Los Angeles, United States | 27th | Marathon |