The Muddy River Rollers (MRR) is a women's flat track roller derby league based in Moncton, New Brunswick.

Muddy River is a member of the Women's Flat Track Derby Association (WFTDA).

[2] It was playing bouts by the following year, when its away bout against the Halifax Roller Derby Association drew in a capacity crowd of eight hundred fans.

[3] In September 2012, Muddy River competed at the Roller Derby Association of Canada's first Atlantic Canada Roller Derby Championship, beating the Fog City Rollers to win the tournament and qualify for the following year's national championship.

[4] Muddy River was accepted as a member of the Women's Flat Track Derby Association Apprentice Program in April 2013,[5] and became a full WFTDA member in October 2014.