Pjanić started his professional career at Metz being there for one season. He signed for side Lyon in 2008 before signing for Roma in 2011 after three seasons at Lyon. During his time in Rome, Pjanić came to be recognized as one of the best midfielders in Serie A. In 2016, Pjanić joined Juventus, and has since been considered an integral player for the team, winning four Serie A titles, two Coppa Italias, and being named in the Serie A Team of the Year for 2015–16, 2016–17, 2017–18 and 2018–19 seasons. He was also named in the 2016–17 UEFA Champions League Squad of the Season, for his role in Juventus's run to the final. Pjanić joined Barcelona in September 2020.