Sergey Sirotkin has started in karting at 7 years old. Already in 2006 he became champion of Moscow, and in 2007 and 2008 was the champion of Russian. Then he moved up to European karting. Sergey raced in various international series, working his way up from the junior ranks to progress through to the KF3 and KF2 category by 2010.

Having turned 14 years old, Sirotkin graduated to single-seaters, racing in the newly launched Formula Abarth series in Italy for Jenzer Motorsport. He made his debut in the middle of the season at Vallelunga, immediately finishing his first race in the points and later added four more point-scoring finishes.

Sirotkin remained in Formula Abarth with Jenzer for a second season. In 2011 the series was developed into two separate classifications: the European and the Italian championship. But prior to the round at Spa, Sirotkin switched to the Euronova Racing by Fortec team. In Italian classification Sirotkin scored 136 points and finished second in the individual competition after failing to catch up with Patrick Niederhauser. In the European classification, he spent all 14 races, ten of which are finished on the podium (5 wins). Thanks to the results shown he earned 175 points and became the champion of the series.

In 2012, Sirotkin continued his collaboration with Euronova Racing into the Auto GP World Series. His first round at Monza saw him qualify on the front row, losing pole position to Adrian Quaife-Hobbs by just 0.04 seconds. Sergey stalled at the start of the first race, but recorded a finish of fourth place in the second race; he also set the fastest lap in both races. At Valencia, he again started behind points leader Quaife-Hobbs, but this time Sirotkin passed him before the first turn, and eventually scored his first win - again setting fastest lap - becoming the youngest Auto GP winner in the championship history. After another fastest lap in the second race, Sirotkin established a record of four consecutive fastest laps; breaking a record previously held by Romain Grosjean. Sirotkin went on to finish the season in third place overall, behind Quaife-Hobbs and Pal Varhaug. He finished the season with two race wins in Valencia and Sonoma, and seven podium finishes. He also recorded his first Street Circuit pole position at the Marrakech.

Sirotkin also participated in the Italian Formula Three Championship driving for Euronova. He recorded two wins at the Hungaroring and Monza, and a further four podium finishes over the course of the season. He finished the season fifth overall in both the European and Italian Series championships.

Same year Sirotkin made his Formula Renault 3.5 debut in his home event at the Moscow Raceway with BVM Target team.

In 2013 Sirotkin spent full season in World Series by Renault 3.5 in the ISR Racing team. He had podiums at Alcaniz and Hungaroring with another three point-scoring finishes to achieve the ninth place in the championship standings.

In July 2013 Sirotkin joined the Sauber team with the aim hold the next season in Formula 1.

In 2014 Sergey joined the Fortec Motorsport team. His Forteс's car often broke and Sergey did not finish in 5 races. Only once, when seeing the checkered flag, Sergey did not got into points. He obtained a spectacular pole and win at his home track Moscow Raceway.

Sergey was also signed by the Sauber F1 Team as test driver. Sirotkin participated in tests that took place in Bahrain on April 8. The Russian driver did 75 laps and covered a distance of over 300 kilometres, recording the 8th fastest time. This result allowed Sirotkin to get the Formula 1 Superlicence. Sirotkin made his race weekend debut in free practice at the 2014 Russian Grand Prix where he recorded the 17th fastest time, only 0,4 slower than his more experienced team-mate Adrian Sutil.

In February 2015, it was announced that Sirotkin would debut in the GP2 series with Rapax.

Having experienced trouble in the first two rounds, Sergey obtained an excellent series of podium finishes on the European tracks. He achieved his first victory at Silverstone by winning the feature race, ending Stoffel Vandoorne's four-race feature win streak. One win, four podiums, pole position and fastest lap allowed him to score 139 points ending third in the overall standings and becoming also the best Rockie of the championship and the Pirelli Award winner.

In 2016, Sergey continued to drive in GP2 Series in the ART Grand Prix team.

Sergey was the only person who could fight with Prema Racing on the sheer speed. However, two mistakes in Barcelona and Monaco, as well as some technical problems and bad lucks at other races heavily affected his fight for the title. Despite the fact that after half of the championship, Sergey was able to lead the championship standings.

This season he has scored two victories in races - at the Hungaroring and at the Hockenheim. In addition, earning 6 podiums, 3 pole positions and 3 fastest laps, Sergey gained 159 points and repeated the previous year's result - took third place in the overall standings.

Sergey continued to work with Renault Sport F1 Team as 3rd and Reserve Driver. His program included plenty of work at the team’s base, developing work at the team’s simulator and many testing days and FP1 practices.

The first time he got behind the wheel on the official tests in Bahrain. During the season, he has participated four times in the F1 first free practice sessions (in Russia, Spain, Austria and Malaysia). In addition, he spent 6 testing days on Renault (Lotus) E20, in addition to that Sergey participated in the Festival of Speed in Goodwood and demonstration run at Silverstone on Renault RE40.

Once in this season Sergey returned to Formula 2 for the race weekend in Baku. He temporarily replaced Alexander Albon in the ART GP team. Weekend for Sergey was not easy due to the technical problems with the car on Friday, but he fought his way back to 10th in feature race and 4th in sprint race.

Also Sergey took part in the legendary "24 Hours of Le Mans". Sergey Sirotkin was a partner of IndyCar driver Mikhail Aleshin and former WEC GTE-Am champion Victor Shaytar for the SMP Racing crew #27, who competed at the Dallara P217. Due to some reliability problems during the night and earlier in the morning SMP Racing team #27 lost than an hour and finished 17th in LMP2 and 34th in the overall standings.

At the end of the Formula 1 season, Sergey was invited by the Williams Racing team to test the Pirelli tires, which were held on the Yas Marina in Abu Dhabi.

Sergey Sirotkin made his debut in F1 with Williams Martini Racing, being signed to the team on January 16, 2018. The 22-year-old SMP Racing driver became a Lance Stroll’s teammate.

The new Williams FW41 car was the slowest in the F1 grid. Lacked downforce, nervously behaved in corners, did not work well with rubber, was too dependent on the track configuration and temperature, but the main thing was to be unpredictable and difficult to manage.

Williams drivers managed to earn points in only two races - in Baku and Monza. In such a situation, the main guideline was the results of the partner. Sergey was able to get ahead of Lance in qualifications with a 13:8 score, did not make serious mistakes during the whole championship, patiently worked with the team and never criticized their work.

Before the Abu Dhabi Grand Prix, it was announced that SMP Racing and Sergey decided not to continue takin part in the Formula 1 World Championships in a joint project with the Williams Martini Racing due to lack of performance and development of the car.

Sergey was included on Audi's line-up for Jerez rookie DTM test on December. He worked with the WRT and drove 91 laps in a day.

Sergey participated in Formula E car test at the Mahindra Racing invitation in Marrakech (Morocco) on 13 January.

29 January was announced that he will join the SMP Racing team in the FIA World Endurance Championship and will drive the #17 car.

Later it was announced that Sergey has been signed as a reserve driver for the Renault F1 Team in the 2019 season as well.