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All nineteen UCI WorldTeams are joined by three UCI ProTeams and the Swiss national team to make up the twenty-three teams that are participating in the race. Each team entered a squad of seven riders, for a total of 161 riders who started the race. Before Stage 4, Intermarché–Wanty–Gobert Matériaux pulled out of the race after a staff member tested positive for COVID-19. 124 riders finished the race.
10 June 2021 — Gstaad to Leukerbad, 172 km (107 mi), 177 km (110 mi)
After the stage, race commissaires handed Julian Alaphilippe a 20-second penalty and a 200CHF fine for taking an illegal feed inside the last 20 kilometres (12 mi) of the stage.
Originally, Rui Costa narrowly beat Andreas Kron in a two-up sprint. However, after the stage, race commissaires relegated Costa for having deviated from his sprinting line and thus impeding Kron's sprint.
On stage 2, Mattia Cattaneo, who was third in the points classification, wore the black jersey, because first placed Stefan Küng wore the yellow jersey as the leader of the general classification and second placed Stefan Bissegger wore the white jersey as the leader of the young rider classification.
On stage 3, Mathieu van der Poel, who was second in the points classification, wore the black jersey, because first placed Stefan Küng wore the yellow jersey as the leader of the general classification.
On stage 4, Stefan Küng, who was second in the points classification, wore the black jersey, because first placed Mathieu van der Poel wore the yellow jersey as the leader of the general classification. For the same reason, Stefan Bissegger wore the black jersey on stage 5.
Before stage 6, Mathieu van der Poel, who was leading the points classification, and Lucas Hamilton, who was leading the young rider classification, both abandoned the race due to illness. As a result, on stage 6, Stefan Bissegger, who was second in the points classification, wore the black jersey, while Eddie Dunbar, who was second in the young rider classification, wore the white jersey.
Final classification standings
Legend
Denotes the winner of the general classification
Denotes the winner of the young rider classification
Denotes the winner of the points classification
Denotes the winner of the most active rider award
Denotes the winner of the mountains classification
^ Stage 8's rerouting increased the race's overall distance from the original distance of 1,015.1 km (630.8 mi).
^ The stage was originally 118 kilometres (73 mi) long, but race organisers rerouted the stage due to weather conditions atop some of the originally included mountains, thereby increasing its distance by 41.5 km (25.8 mi).
Stefan Küng (SUI)
Mathieu van der Poel (NED)
Richard Carapaz (ECU)
Andreas Kron (DEN)
Rigoberto Urán (COL)
Maximilian Schachmann (GER)
Michael Woods (CAN) 
Domenico Pozzovivo (ITA)
Rui Costa (POR)
Joey Rosskopf (USA)
David de la Cruz (ESP)
Eddie Dunbar (IRL) 
Andreas Leknessund (NOR)
Stefan de Bod (RSA)
Stephen Williams (GBR)
Team Bahrain Victorious
Astana–Premier Tech
Deceuninck–Quick-Step
UAE Team Emirates
Total Direct Énergie