Fish won six tournaments on the main ATP Tour and reached the final of four Masters Series events: Cincinnati in 2003 and 2010, Indian Wells in 2008, and Montreal in 2011.

At the 2004 Summer Olympic Games, Fish won the silver medal in men's singles, losing the final to Nicolás Massú.

In 1984 a Minneapolis TV station ran a profile of Fish, at the age of two, hitting tennis balls from the baseline over the net.

He earned his first title on the ATP Tour in 2002 playing doubles in the U.S. Men's Clay Court Championships in Houston, Texas, with Andy Roddick.

At the 2004 Summer Olympics, Fish earned a silver medal having defeated Juan Carlos Ferrero and Fernando González to reach the final.

He won the tournament, defeating eighth seed Juan Mónaco, Rainer Schüttler, Vince Spadea, Tommy Haas, and Jürgen Melzer in the final 3–6, 6–4, 6–3.

At Wimbledon, Fish signaled his return to professional status as he reached the third round, defeating fellow American Robby Ginepri and Dutch player Melle van Gemerden.

Fish made waves on the first day of the tournament by knocking off Ivan Ljubičić, the fourth seed, and had an easy win in the third round when his heavily favoured opponent Wayne Arthurs retired in the opening set.

Fish won against Indian Rohan Bopanna and Australian Peter Luczak, and received a walkover from Czech Tomáš Berdych.

Fish fell to Jarkko Nieminen in the third round of the Australian Open after a code violation caused him to lose his composure.

Fish then went on to make a quarterfinal showing at the 2008 Delray Beach International Tennis Championships, before losing to long-time friend and wild-card entry Robby Ginepri.

1 Roger Federer in the semifinals in what Fish described as "a great win,"[5] after failing to beat the Swiss player in five previous matches.

Fish won his fifth doubles title, partnering Mark Knowles of the Bahamas at the Regions Morgan Keegan Championships in Memphis.

The next week, ranked as the top seed, he won his third singles title at the Delray Beach International Tennis Championships against first-time finalist Evgeny Korolev.

In the 2009 BNP Paribas Open, Fish received a first-round bye, only to be eliminated in the second round by unseeded Frenchman Jérémy Chardy.

In April, Fish played in the 2009 U.S. Men's Clay Court Championships, but was knocked out in the first round by Björn Phau of Germany.

In doubles, he and partner James Blake advanced to the semifinals, before losing to the defending and eventual champions Daniel Nestor and Nenad Zimonjić.

It was the first tournament in Atlanta in over a decade, and in the semifinal and final rounds, Fish defeated Andy Roddick (whom he had not beaten in eight consecutive career meetings), who was the top seed, and John Isner, who played collegiate tennis for nearby University of Georgia.

By defeating del Potro and reaching the quarterfinals in Miami, Mardy Fish overtook Andy Roddick as the highest-ranked American player on the tour.

At the 2011 Farmers Classic on July 31, 2011, Fish faced Ernests Gulbis for the title, having defeated fellow American teenager Ryan Harrison in the semifinals.

In August at the 2011 Rogers Cup, Fish reached his fourth Masters series final, defeating Feliciano López, Ernests Gulbis, Stanislas Wawrinka, and Janko Tipsarević, 6–3, 6–4, in the semifinal.

Fish continued his impressive run on the American hard courts with a comfortable 6–0, 6–2 victory in the second round of the 2011 Western & Southern Open against former world no.

He reached the semifinals in Tokyo in October, defeating Ryan Harrison, Ernests Gulbis, and Bernard Tomic, before falling to Rafael Nadal.

On May 23, he underwent a cardiac catheter ablation in Los Angeles to correct faulty electrical connections in his heart, in which those spots were cauterized in order to prevent short circuiting.

He defeated Go Soeda, Nikolay Davydenko, and Gilles Simon before withdrawing for health reasons before his fourth-round match with top seed Roger Federer.

Fish went to Vero Beach High School with country music star Jake Owen, with whom he remains good friends.

Perched high in the cheap seats, relatively speaking, were a raucous band of shirtless fans, each one with a letter that collectively spelled out, Go Fish.

In 2022, Fish received a sponsor exemption to play in the 3M Open, a PGA Tour event in his home state of Minnesota.

On the final hole, a fan heckled Fish while hitting his tee shot, who apparently had money on Curry to win the tournament.

[38][39] *Fish withdrew from the 2012 US Open prior to his fourth-round match (not counted as a loss) Current through the 2012 ATP World Tour Finals.