Roberto Martinez will now serve in the same capacity for Portugal's national team. Most recently, he was the head coach of Belgium.
The details were posted on the Portuguese Football Federation's Facebook page on Monday.
A picture of the Spaniard with the tagline, "A new Leader at the service of Portugal: welcome, Mister Roberto Martinez!" was attached to the message.
After losing to Qatar in the World Cup group stage, Martinez, 49, announced his resignation as Belgium's coach. He succeeds Fernando Santos, who led Portugal to success at Euro 2016 and the first UEFA Nations League championship in 2019.
With Portugal, who field some of the most well-known players in football, the former Everton head coach, who was in charge of overseeing a multitude of talents during his time with Belgium, will have even greater challenges. Among these players are Bernado Silva, Bruno Fernandes, and captain Cristiano Ronaldo.