June On 13 June, Atlético reached an agreement with
Antoine Griezmann for the extension of his contract for one more season, through to 30 June 2022. On 30 June, Atlético and
Alessio Cerci reached an agreement to terminate Cerci's contract.
July Atlético reached an agreement with
Saúl to extend contract for five additional seasons, through 30 June 2026. On 5 July, Atlético and
Real Madrid reached an agreement for the transfer of
Théo Hernandez. That same day, the club announced an agreement with
Fernando Torres, who signed a one-year contract for the 2017–18 season. On 12 July, the club signed
Vitolo to a five-year contract after Vitolo repudiated his contract with
Sevilla. Due to
FIFA's sanction forbidding Atlético from registering football players during the current summer market, Vitolo would play the first half of the season on loan at
Las Palmas and joined Atlético on 1 January 2018.{{cite news|url=http://en.atleticodemadrid.com/noticias/agreement-with-vitolo-until-2022|title=Agreement with Vitolo until 2022 --> ==Kits==