In 2007, just fifteen years old, Muñoz made his debut in single-seaters, racing in the Formula TR Pro Series.

[3] Along with his Formula Renault campaigns, Muñoz competed in three rounds of the European F3 Open Championship, driving for Porteiro Motorsport.

[4] 2010 saw Muñoz move to the Formula 3 Euro Series, competing for Mücke Motorsport, joining Roberto Merhi at the team.

[6] He captured two victories, including one on the oval at Auto Club Speedway and a win from the pole in Edmonton, in addition to three other podium finishes on his way to fifth in the championship.

Muñoz got his first IndyCar win in the rain-shortened Race 1 of the Detroit Belle Isle Dual Grand Prix on 30 May 2015.

[8] After a distant second-place finish to teammate Alexander Rossi in the 2016 Indianapolis 500, Muñoz left Andretti Autosport after the 2016 IndyCar season ended.