On 16 May 2017, Stockdale was named in the Ireland squad for the 2017 Summer Tour. On 10 June 2017, Stockdale made his senior debut for Ireland when he played against the United States in a one-off test in the Red Bull Arena, New Jersey, scoring a try in the 55–19 Irish victory. Stockdale played his first home game for Ireland on 11 November 2017, against the South Africa where he scored a try. Two weeks later in the same November series he won 'man of the match' award scoring two tries in Ireland's 28–19 victory over Argentina.