Additionally, at the 2016 Rio Olympics, López won the gold medal in men's doubles for Spain partnering with Rafael Nadal.

In his ATP debut at Stuttgart as a qualifier ranked 236, López defeated Richard Fromberg, eventual French Open finalist Guillermo Coria, two-time French Open winner Sergi Bruguera, and Alberto Martín en route to the semifinals, where he lost to Guillermo Cañas.

That was in 2004, when he reached the final of the Open de Tenis Comunidad Valenciana partnering with his friend and countryman Feliciano López.

In 2012, López and Rafael Nadal, again won the doubles final at Indian Wells, defeating Americans John Isner and Sam Querrey.

In 2016 Rio Olympics he teamed up with Rafael Nadal to win the gold medal in the men's doubles event.

Alongside his partner Feliciano López, they defeated the Bryan brothers (Bob and Mike) in the quarterfinals of the men's doubles tournament, the score 7–6(7–2), 4–6, 6–3.

[3] The pair then lost in the semifinals against fellow countrymen Pablo Carreño Busta and Guillermo García López in straight sets.

At the 2017 US Open, Marc and Feliciano went one step further than the previous year by again defeating the Bryan brothers en route to the final where they lost to Jean-Julien Rojer and Horia Tecău.

[8] In August 2021, López welcomed his first child with María García-Planas Albert, a former college tennis player at the Loyola Marymount University.