On 23 January 2017, Stander was named in the Ireland squad for the opening two rounds of the 2017 Six Nations Championship. On 11 February 2017, Stander scored a hat-trick of tries in Ireland's 63–10 win against Italy in the Stadio Olimpico, Rome, earning the Man-of-the-Match award. This was the first hat-trick scored by an Irish back-row since Brian Robinson's against Zimbabwe at the 1991 Rugby World Cup. It was also the first hat-trick scored by an Ireland player in the Six Nations since Brian O'Driscoll's against Scotland in the 2002 tournament. Furthermore, it was the first hat-trick scored by a forward in Six Nations Championship history and the first by a forward since Frenchman Michel Crauste's in the 1962 Five Nations Championship. Stander's teammate, Craig Gilroy, also scored a hat-trick in the match, making Ireland the first team since England in 1914 to have two hat-trick scorers in a Five or Six Nations game. On 18 March 2017, Stander made a late switch to Number 8 for Ireland when Jamie Heaslip pulled out of the game against England during the warm-up. Ireland went on to win the game in the Aviva Stadium 13–9 and, in doing so, denied England consecutive Grand Slams in the Six Nations. Following his performances in the tournament, Stander was nominated for the 2017 RBS 6 Nations Player of the Championship award, alongside teammate Conor Murray.