His career started in the karting world in 1999 and he began with single-seaters in 2008, when he took part in the English Formula Renault with the Fortec team. At the end of the season he took part in the Winter Series in both the Portuguese and the English Formula Renault. That year, Calado also participated in three Eurocup Formula Renault 2.0 races with the Fortec team and went on to compete in the English Formula 3 championship for the 2010 season with the Carlin team. In 2011, he changed to the GP3 Series as standard bearer for the Lotus ART team, with which he debuted in GP2 in the 2011 finals held in Abu Dhabi.

In 2012, he took fifth place in the championship, winning at Sepang and Hockenheim and reaching the podium another five times. In 2013, Calado was the test driver for Formula 1’s Force India and then the third driver for the Indian team. In GP2 (again at the ART Grand Prix), he won two more races, taking third place in the championship. In 2014, the Englishman joined Davide Rigon at the wheel of one of the 458 Italia GTEs lined up by the AF Corse team in the World Endurance Championship (WEC), where he reached the podium five times and contributed to Ferrari's victory in the Constructor Championship. In 2015, again with Rigon, he competed in the WEC with the AF Corse number 71 Ferrari, finishing second at the 24 Hours of Le Mans, gaining three more podiums and finishing fourth in the drivers championship.

In 2016, he took on the WEC at the wheel of the Ferrari 488 GTE number 51 together with Gianmaria Bruni, while in 2017 he became the GT class world champion with Alessandro Pier Guidi, thanks to three victories with the AF Corse team’s 488 GTE. In the WEC, Calado participated in some IMSA races, including the Daytona 24 Hours where he finished in second place. In 2018, James took part in the WEC Super Season, where he won at Silverstone and competed in the IMSA championship at Daytona and Sebring with the Risi Competizione team. He made a decisive contribution to the Japanese CarGuy team’s victory at the Asian Le Mans Series, with which he had four victories in as many races, together with Takeshi Kimura and Kei Cozzolino. In 2019, he finished the WEC Super Season in second place with Alessandro Pier Guidi, a result enhanced by the victory at the 24 Hours of Le Mans and rounded off a very positive year with a triumph in the Petit Le Mans. In 2020, the British driver took part in both FIA WEC Season 8 and the GT World Challenge Endurance Cup with the 488 GTE and 488 GT3 Evo 2020 of AF Corse.

The British driver claimed the FIA World Endurance Championship title again in 2021, with Alessandro Pier Guidi in the AF Corse 488 GTE, after an intense season embellished by a victory in the 24 Hours of Le Mans. In 2022, Calado will be at the wheel of AF Corse’s 488 GTE in the FIA WEC World Championship and Iron Lynx’s 488 GT3 Evo 2020 in the GT World Challenge Europe.

James Calado’s memorable performances, such as the 6 Hours of Spa, brought a splendid repeat win in the World Endurance Championship alongside Pier Guidi. In his third world championship, the British driver also competed in GT WC Europe and a few races in IMSA, besides developing the 499P.