Sarah Michelle Ryan, OAM (born 20 February 1977) is an Australian former sprint freestyle swimmer, who won relay medals at three consecutive Olympics from the 1996 Summer Olympics to the 2004 Summer Olympics.
Coming from Adelaide, South Australia, Ryan attended the Catholic Mount Carmel College, before moving to the Australian Institute of Sport, Canberra, in 1993 after being awarded a scholarship. She gained selection for Australia the following year at the 1994 Commonwealth Games in Victoria, British Columbia.
In 1996, in Atlanta, she came sixth in the 100-metre freestyle, and was a member of the 4×100-metre medley relay along with Susie O'Neill, Samantha Riley and Nicole Stevenson, which claimed silver behind the United States team. At the 1998 Commonwealth Games in Kuala Lumpur, Malaysia, she was a part of the team which won the 4×100-metre freestyle relay only days after the death of her father.
In 2000, in Sydney, Ryan failed to qualify for the finals of either the 50- or 100-metre freestyle. She was a member of the 4×100-metre freestyle relay which placed sixth and collected a silver for swimming in the heats of the 4×100-metre medley relay, being replaced by O'Neill in the final, again second to the Americans.
In 2001, possibly her most savoured moment came at the FINA World Championships in Fukuoka, Japan, when she anchored the 4×100-metre medley relay team with Dyana Calub, Leisel Jones and Petria Thomas to a long-awaited win over the American team. It was the first time that Australia had defeated the Americans at either Olympic or World level in the event. The year 2002 broke another drought, with Ryan being part of a 4×100-metre freestyle team alongside Jodie Henry, Alice Mills and Thomas, which defeated the Americans for the first time since 1956.