In what year did Cristiano Ronaldo make his senior debut for Portugal? Cristiano Ronaldo made his senior debut for Portugal in 2003.
The debut took place on 20 August 2003, when Portugal defeated Kazakhstan 1–0 in a friendly at the Estádio do Algarve. Ronaldo was 18 years old and had already attracted attention through Sporting CP's youth system and first team.
His international breakthrough continued at UEFA Euro 2004, hosted by Portugal. He scored his first senior international goal against Greece in the tournament's opening match on 12 June 2004. He later became Portugal's captain and its most prolific international goalscorer.
The year is easy to confuse with other important debuts. Ronaldo made his Manchester United debut in August 2003, only days before his Portugal appearance, while his senior club debut for Sporting came in 2002. The question refers specifically to the Portugal senior national team.