Arão started his youth career playing for São Paulo and Corinthians, where he had his first professional experience, although Arão spend most of his following years playing on loan for different Brazilian clubs. Including a very consistent 2015 season with Botafogo winning the 2015 Campeonato Brasileiro Série B.
In 2016 Arão was involved in a very complicated transfer to Flamengo with Botafogo complaining about the way their rivals approached the player. The situation is still to be solved in the Brazilian justice court.[3]
Career
Corinthians
Formed in the São Paulo, Willian was the new reinforcement in midfield of Corinthians in 2011. Featured in the Copa São Paulo de Futebol Júnior in 2011, the player has good quality in the tackle and can exercise its left side.
On 10 January 2015, Willian Arão joined Botafogo on loan until the end of 2015 season.[10][11] At Botafogo Arão had the best season of his career so far playing a total of 58 official matches,[12] including 35 Série B matches scoring 5 goals, culminating with 2015 Série B title.[13] He was one of the team most important players calling the attention of several other Brazilian clubs.
Flamengo
On 1 January 2016, Willian Arão joined Flamengo on a free transfer.[14][15] He instantly earned a first team spot being selected to the 2016 Bola de Prata.
On 28 December 2016 Arão signed another three-year contract with Flamengo until December 2019.[16] In 2018 Arão lost space in the Flamengo's first team and the Brazilian press speculated a possible transfer. On May Internacional showed interest in signing him on loan, although the transfer didn't happen.[17]
On 24 July 2018 Flamengo and Olympiacos agreed Arão's transfer for a sum of €2.5 million.[18] A few days later, the transfer was canceled, since Arão and Olympiacos could not agree on how his salary would be paid.[19]
On 14 July 2022, Arão moved abroad for the first time in his career, signing a two-year contract with an option for an additional year with Turkish club Fenerbahçe.[20]
Panathinaikos
On 17 August, Arão moved from Fenerbachçe to Greek side Panathinaikos on a two-year contract.