On 14 March 2019, Real Madrid announced that they had signed Militão to a six-year contract effective 1 July 2019 after paying a €50 million transfer fee to Porto. He made his debut on 14 September, coming on as a substitute for Sergio Ramos for the last half-hour in a 3–2 home victory over Levante. He made 15 appearances during the league season as Real Madrid won the 2019–20 La Liga.