Sock regularly played doubles with Canadian tennis player Vasek Pospisil until July 2016 and together they won the 2014 Wimbledon Grand Slam championship, a victory that helped vault them into the Top 10 of the ATP Doubles rankings. Additionally, he won the 2011 US Open mixed doubles title with fellow U.S. player Melanie Oudin.
At the 2016 Olympics, he won the gold medal in the mixed doubles with Bethanie Mattek-Sands and captured a bronze medal in the men's doubles with Steve Johnson.
Sock graduated from Blue Valley North High School in Overland Park, Kansas. He was 80–0 in his KSHSAA 6A high school tennis career, winning four consecutive state championships.
He had moved to Kansas from Nebraska at the age of 12 to train at the Mike Wolf Tennis Academy.
As a junior, Sock reached No. 22 in the world combined rankings in October 2010. He played his first ITF junior tournament in October 2008, at age 16, at the Pan American Championships. In the 2009 US Open, his third junior tournament, he reached the semifinals of the junior doubles with Matthew Kandath, and the third round of the junior singles.
Sock played relatively infrequently on the junior circuit, however, entering just two further tournaments: the Dunlop Orange Bowl in 2009 and the junior singles at the 2010 U.S. Open. At this tournament, he received a wildcard entry, but proceeded to the final. There, he defeated fellow American Denis Kudla in three sets, to become the first American winner of the junior championships since Andy Roddick in 2000. He won the Boy's Junior National Tennis Championship in 2010 and 2011, earning a wildcard in both years for the main draw of the US Open.
Sock began playing in Futures tournaments in 2009, winning his first senior tournament on that circuit in November 2009. He entered his first qualifying draw for an ATP tournament at the 2010 Miami Masters. His first main-draw match as a professional came at the 2010 US Open, where he lost to Marco Chiudinelli. Sock finished the 2010 season ranked 878th in the world.
In 2011, he reached the final of the USA F3 tournament. He also began to play in a few tournaments at Challenger level, with his biggest success being a quarterfinal at the Dallas Challenger. He also competed in the main draw of the 2011 Miami Masters. As 2010 US Junior champion, he received a wildcard into the 2011 US Open, winning his first ATP match against Marc Gicquel in four sets. He advanced to play his idol Andy Roddick, a fellow Nebraskan in the second round, however he lost in straight sets. Sock's real breakthrough came in the mixed doubles, however, where he advanced to the final alongside Melanie Oudin, defeating the defending champions Bob Bryan and Liezel Huber in the second round. In the final, Sock and Oudin defeated Gisela Dulko and Eduardo Schwank in three sets to win their first Grand Slam title, both individually and together.
After winning his first Grand Slam title, Sock returned to competing on the Challenger Tour. His most successful tournament was the Sacramento Challenger, in which he reached in the quarterfinals of the singles tournament and, partnering Nicholas Monroe, the final of the doubles tournament. Sock finished 2011 ranked no. 381 in the singles, and no. 370 in the doubles.
In 2012, Sock won the Futures tournament at Plantation, as well as losing in the doubles final. Stepping back up to the Challenger level, he competed at the Honolulu Challenger, making the quarterfinals of the singles tournament and, alongside Nick Monroe, once again made the final of the doubles tournament.
Sock played in the 2012 Campbell's Hall of Fame Tennis Championships, and lost in the second round to Izak van der Merwe. Sock's next tournament was the 2012 BB&T Atlanta Open. He upset the number 7 seed of the tournament, Alex Bogomolov, Jr.. He made it to the quarterfinals where he lost to John Isner. At the US Open, Sock defeated the number 22 seed, Florian Mayer, in the first round when Mayer retired. He then went on to defeat world number 85 Flavio Cipolla of Italy in straight sets, setting up his first ever Grand Slam third round match against 11th seed Nicolás Almagro, however he was defeated in 4 sets. In the final two months of the 2012 season Sock reached his first two Challenger Tour finals, winning at Tiburon in October and finishing as runner-up in the November Champaign-Urbana Challenger. These finals helped him rise to the top 150 for the first time.
Sock had a slow start to 2013, losing in the qualifying of the Brisbane International and the 2013 Australian Open. However, he received a wildcard entry into the U.S. National Indoor Tennis Championships, in which he gained his first wins of the season in reaching the quarter-final, the second of his career. In the doubles competition at the same tournament Sock teamed up with James Blake, also a wildcard entry, reaching the final where the pair lost to the Bryan Brothers. Sock made it through three rounds of qualifying without dropping a set to get into the main draw of the 2013 French Open. In the first round he defeated the accomplished player Guillermo García-López in only 1 hour and 59 minutes. He then lost to the 35-year-old veteran Tommy Haas in straight sets. He tried to qualify for Wimbledon for the first time, but although seeded second, lost to Mischa Zverev. He returned to the US to win his 2nd career Challenger level title in Winnetka, IL on July 6, allowing him to break into the top 100 for the first time in his career. At the US Open, he defeated Philipp Petzschner in the first round, going 5 games to 2 up in the third set before Petzschner retired. Sock then went on to beat Maximo Gonzalez, however lost to 18th seed Janko Tipsarević in the third round. Following the US Open, his ranking rose to no. 86.
Sock began his 2014 campaign in Auckland, opening his campaign against Frenchman Adrian Mannarino. His aggressive playing style was too much for his opponent, winning in straight sets to set up a match with German second seed Tommy Haas. In a considerable upset, Sock defeated the world number 12 in straight sets to advance to the quarterfinals. There he faced Spaniard Roberto Bautista-Agut, however lost in straight sets. He then gained his first direct entry into the Australian Open main draw, after having failed to qualify the previous year. He started strongly, defeating German Tobias Kamke in four sets in his opening match before losing to former world number 7 Gaël Monfils in the second round.
At the 2014 Wimbledon Championships, Sock at the last moment teamed up with Canadian Vasek Pospisil, where they eventually went on to win the men's doubles title in a five-set final against the top seeds, Bob and Mike Bryan.
Sock beat Bernard Tomic and world no. 6 Kei Nishikori to reach the third round of the 2014 Shanghai Rolex Masters.
In December, he underwent hip surgery, sidelining him for the start of the 2015 season.
After missing the first two months of 2015 ATP season, Sock made his return at 2015 BNP Paribas Open. He won his first three matches, including victories over seeded players Gilles Muller and Roberto Bautista Agut. He lost in the fourth round to second seed Roger Federer in straight sets. In doubles, he resumed his partnership with Pospisil to win their first Masters level tournament.
His second tournament was the 2015 Miami Open, in which he won his first two matches, including beating 21st seed Fabio Fognini, before losing to Dominic Thiem in the third round. He made the doubles final, again partnering with Pospisil, but lost in a third-set tiebreaker to the Bryan brothers.
Sock continued his successful start to the year by winning his first ATP tournament, the 2015 U.S. Men's Clay Court Championships. En route to the title, he knocked off second seed, Roberto Bautista Agut, fifth seed, Santiago Giraldo, third seed Kevin Anderson, and defeated eighth seed Sam Querrey in the final. He then competed in the 2015 Mutua Madrid Open in Spain, advancing to the second round by beating wildcard Pablo Andujar in straight sets, before losing to 12th seed Jo-Wilfried Tsonga.
At the French Open, Sock upset 10th seeded Grigor Dimitrov in the first round in straight sets. He continued his run by beating Pablo Carreño Busta in four sets and teenager Borna Ćorić in straight sets. At age 22, He became the youngest American to reach the round of 16 at the French Open since Pete Sampras in 1993. In the fourth round, he lost in four sets to defending champion Rafael Nadal.
Sock collapsed at the US Open, and was forced to retire against Ruben Bemelmans, Bemelmans-Sock.
On November 2, Sock reached the top 25 for the first time in his career. For the second straight year, he and Pospisil finished 9th in the ATP Doubles Race to London rankings, just barely failing to qualify for the year-end championship tournament.
Sock began his season at the 2016 Hopman Cup, representing the USA alongside Serena Williams, who was ultimately replaced by Victoria Duval due to injury. In the round-robin stage, Sock's only singles win was over Jiří Veselý. Sock and Duval recorded wins in the mixed doubles over Ukraine and the Czech Republic. They did not proceed to the final.
At the Auckland Open, Sock reached his third career ATP final by beating a top-10 player David Ferrer for the second time in his career, despite losing the first set and battling flu-like symptoms. He ended up retiring in the final due to that illness. Sock began the clay-court season by reaching his second consecutive final in Houston, but was unable to defend his title after struggling with an injury in the last set of the final.
Sock played in all three tennis competitions at the Olympic Games in Rio de Janeiro. Despite losing in the first round in singles, he earned a bronze medal in doubles with Steve Johnson and a gold medal in mixed doubles with Bethanie Mattek-Sands.
At the Shanghai Masters, Sock defeated Milos Raonic for the first time in their last nine matches to reach his first career Masters quarterfinal. With this run, he became the top-ranked American for the first time in his career.
Once again, Sock opened up the season with the Hopman Cup and the Auckland Open. He reached the final at the Hopman Cup with Coco Vandeweghe while dropping just one set in the three round-robin matches, but lost in the final to the French team of Richard Gasquet and Kristina Mladenovic. Sock then followed this performance with an even better result at the Auckland Open by reaching the final for the second year in a row, this time winning the title against João Sousa. With the win, he moved into the top 20 for the first time. Sock finished his stretch down under by making his first appearance in the third round of the Australian Open, where he lost to Jo-Wilfried Tsonga.
In February, Sock returned home to the United States where he helped the Davis Cup team sweep their 1st-round rubber against Switzerland. At the end of the month, he played at the Delray Beach Open and won his second title in two months after Milos Raonic withdrew from the final with a hamstring injury. This title took Sock to a career high of 18 in the ATP rankings.
Sock continued his impressive streak of deep runs in Masters events by reaching his first career Masters semi-final at the BNP Paribas Open. Along the way, he upset No. 13 Grigor Dimitrov and No. 5 Kei Nishikori, the latter of which was his first career victory over a Top 5 opponent.
On several occasions, Sock has conceded points where he believed the linesperson made an incorrect call.
One particular instance of this sportsmanship came at the 2016 Hopman Cup. During the match against Lleyton Hewitt, Hewitt was serving to stay in the first set when his first serve at 30–0 was called out by the chair umpire. Prior to Hewitt hitting his second serve, Sock said: "That was in if you want to challenge it." The review showed the serve to be in, giving Hewitt the point.
Later in the year, Sock awarded a point to Richard Gasquet at the Paris Masters on an ace that was called out, saving Gasquet the need to use a challenge. The review confirmed that the serve did land in the box on the line.
Sock is primarily an aggressive baseliner. He can be considered a complete baseliner with both offensive and defensive abilities. The topspin on his forehand side helps him move his opponents far back behind the baseline to control points. His forehand and serve are his biggest weapons, and he also boasts an impressive second serve. He uses his groundstrokes either to overpower opponents from the baseline or to move them around the court and look for a winner. He can also flatten out both his forehand and his backhand to devastating effect, but Sock prefers to hit with controlled spin instead. He often hits "whiplash" forehands, where he uses his body-rotation and elbow to generate tremendous pace and topspin with a minimal take back.
Retired American tennis player Andy Roddick has remarked that he and young Sock have similar playing styles, saying, "[Sock] kind of has the half take up with the serve. He's got the flailing elbow on the forehand and the backhand." Sock feels that he and Spaniard Rafael Nadal actually have a more similar playing style, stating in an interview last year that "Nadal prefers the forehand to the backhand and hits with incredible spin. I also like to hit with more spin than pace and prefer my forehand."
Sock has a very strong service game, being able to hit serves at speeds of up to 227 km/h (141 mph). He is able to also hit very powerful and consistent kick serves.
He has excellent touch at net, being able to hit volley winners with ease. While he does not come to net often, in recent months he has played a great deal of doubles, both improving his net game and showcasing his impressive reflexes. This improved net game helped him and Vasek Pospisil win the 2014 Wimbledon doubles title.
Furthermore, Sock is very fast around the court, and is particularly good at running around his backhand to hit powerful inside-in or inside-out forehands. His great court speed allows him to retrieve many shots and use his forehand, his main weapon from the baseline, more frequently. Sock aggressively slides his left foot on the ground when running to his forehand, which wore a hole in his sock and shoe, and drew blood, at the 2015 BNP Paribas Open.
Some commentators have remarked that his technique on the forehand, while quite effective, actually hinders his ability to hit returns well. If Sock has a successful singles career, it will be in spite of, not because of, his technique, according to retired American tennis champion and now commentator Jim Courier.
Current through the 2017 US Open.