Alex Sandro is a part of the golden Atlético Paranaense youth setup, which has produced a great amount of defenders in very little time, with Raul, Manoel, Ronaldo Alves, Carlão and Bruno Costa all making themselves known in 2009. After being a part of the Brazil under-18 setup, Alex Sandro was called-up to the under-20 side in August 2009, alongside teammates Raul, Renan Foguinho and Gabriel Pimba. He made his debut in a friendly match at 18 years of age. He was a member of the teams that won the 2011 South American Youth Championship in Peru, as well as the 2011 FIFA U-20 World Cup in Colombia, also featuring in the final of the tournament against Portugal, which Brazil won 3–2 in extra-time.He also represented the Brazil under-23 side, at the 2012 Summer Olympics in London, where he made 3 appearances, including one in the final against Mexico, in which Brazil was defeated 2–1. Alex Sandro made his senior international debut on 10 November 2011 in a 2–0 away win over Gabon.