In the 2021 Tour of the Alps, there were five classifications, of which four had jerseys awarded to the leaders and winners; the colors of each jersey were derived from the company that sponsored each jersey. The
general classification (GC) ultimately decided which rider won the overall race, and was calculated by adding up each rider's finishing time on each stage and deducting any bonus seconds accrued. For each stage, the top three finishers got ten, six, and four bonus seconds, respectively, taken off their GC time. The rider with the fastest time after each stage and at the end of the race wore the yellow jersey, sponsored by Italian apple-producing consortium
Melinda. The second classification was the
mountains classification. Points were accumulated by being one of the first riders to summit certain climbs, which were marked as either third, second, and first-category climbs, in order of increasing difficulty. Each of the five stages had two designated climbs with points on offer; of these ten climbs, three were first-category, five were second-category, and two were third-category, for a maximum of 66 points that could be obtained by any one rider. The rider who accumulated the most mountains classification points after each stage and at the end of the race wore the light blue jersey, sponsored by Italian bank
Gruppo Cassa Centrale. The
young rider classification was based on and calculated the same way as the general classification, although only under-23 riders, born on or after 1 January 1998, were eligible to contest this ranking. The highest placed under-23 rider in the GC after each stage and at the end of the race wore the white jersey, sponsored by the Austrian branch of the safety and workwear clothing manufacturer
Würth Modyf. The other points-based classification was the sprints classification. Each of the five stages featured one intermediate sprint, which offered six, four, and two points, respectively, to the first three riders to cross the sprint line, for a maximum of 30 points that could be obtained by any one rider. The rider who accumulated the most sprints classification points after each stage and at the end of the race wore the red jersey, sponsored by Italian sports news company
PMG Sport. The fifth and last classification was the
team classification. For this classification, the times of the first three finishers for each team were added together, and the leading team after each stage and at the end of the race was the team with the lowest cumulative time. No special jerseys or jersey numbers were awarded to the leaders and winners of this classification. • On stage 3,
Alessandro De Marchi, who was second in the mountains classification, wore the light blue jersey, because first-placed
Simon Yates wore the green jersey as the leader of the general classification. == Final classification standings ==