In the following season, Iwobi changed his squad number from 45 to 17, after Alexis Sánchez took number 7 from the departing Tomáš Rosický. He went on to feature throughout Arsenal's victorious FA Cup campaign of 2016–17, winning 2–1 against Chelsea in the final. He achieved further success with Arsenal in the 2017 Community Shield, in which Arsenal beat Chelsea on penalties.