Valencia played for Ecuador's under-22 national team at the 2011 Pan American Games.

Valencia made his senior international debut against Honduras in an international friendly.

Valencia scored his first senior international goal against Honduras during the 2014 FIFA World Cup qualification campaign.

Valencia played in the 2014 FIFA World Cup, scoring three goals for Ecuador.

Valencia became Ecuador's all-time top goal scorer by scoring his 32nd and 33rd international goals against Bolivia in a 2022 World Cup qualification match.

Valencia scored the first goal of the 2022 FIFA World Cup and became the first South American player to score in six consecutive World Cup outings.

Valencia scored the only goal in Ecuador's victory over Peru in the 2026 World Cup qualifiers.