World Championship titles were awarded to the leading manufacturers and drivers in both the prototype and grand tourer divisions.

[4] The decision to run a six-round series was made to save on costs due to the financial impact of the pandemic.

[5] The 1000 Miles of Sebring was initially scheduled for 19 March 2021 as the first round of the season, but was cancelled in response to the COVID-19 pandemic and replaced by a race of the same length at Portimão on 4 April 2021.

[8] The 6 Hours of Fuji was cancelled due to ongoing travel restrictions in Japan, and was replaced by a 6-hour event in Bahrain.

[17] The cars have a minimum weight of 1,030 kg (2,270 lb), and power output is capped at 680 hp (510 kW) in order to achieve a benchmark lap time of three minutes and thirty seconds at the Circuit de la Sarthe.

[18] Toyota announced plans to enter the championship under the Hypercar regulations with a bespoke car based on the GR Super Sport Concept.

[20] In June 2020, boutique car manufacturer Scuderia Cameron Glickenhaus committed to a two-car effort with the SCG 007 LMH, in partnership with 1989 24 Hours of Le Mans winners Sauber Motorsport, 15-time Le Mans winners Joest Racing, and engine specialists Pipo Moteurs.

[25][26][27] Aston Martin initially planned to enter a car based on the Valkyrie road-going model.

[46] Entries in the LMP2 Pro-Am Cup, set aside for teams with a Bronze-rated driver in their line-up, are denoted with Icons.

A single bonus point was awarded to the team and all drivers of the pole position car for each category in qualifying.