| Birth Date: | 16 April 1982 |
| Sport: | Athletics |
| Event: | 4 × 400m Relay |
Marian Heffernan (born 16 April 1982) is an Irish athlete who competed in the women's 4 × 400 metres relay at the 2012 Summer Olympics.[1] Heffernan is fifth in the all-time Irish record books for the women's 400 metres.
She is married to Irish Olympic race walker Rob Heffernan, with whom she has a son, Cathal, who is a footballer.[2]