Sinéad C. Russell (born June 15, 1993) is a Canadian competition swimmer from Burlington, Ontario who swam for the Oakville Dolphins swim club in Oakville, Ontario.

In the semifinals, she was in first position after the first length, touching the wall before eventual gold medal winner Missy Franklin, but lost speed and came third with a time of 2:08.76, which was still enough to qualify her for the 8th and final spot in the final.

Russell attended the University of Florida on an athletic scholarship, and swam for coach Gregg Troy's Florida Gators swimming and diving team in National Collegiate Athletic Association (NCAA) and Southeastern Conference (SEC) competition in 2013 and 2014, while continuing to swim at the international level with Swim Canada.

Russell was sidelined with a blood clot in her brain in mid-January 2015.

She is the younger sister of Colin Russell, another Canadian swimmer who competed in the 2008 and 2012 Olympics.