Mackenzie Elizabeth Arnold (born 25 February 1994) is an Australian professional soccer player who plays as a goalkeeper for West Ham United in the English FA WSL and the Australia women's national team, the Matildas. She previously played for Arna-Bjørnar in Norway's Toppserien as well as Brisbane Roar, Perth Glory, Western Sydney Wanderers, and Canberra United in Australia's W-League. Early life Born on the Gold Coast, Arnold attended Palm Beach Currumbin High School. Club career In 2012, Arnold joined Canberra United from Perth Glory ahead of the 2012–13 W-League. Arnold joined Western Sydney Wanderers in 2013. However, she was later ruled out for a significant amount of the season after suffering a deep cut to the leg in the carpark following a match in the 2013 AFC U-19 Women's Championship. Arnold returned to Perth Glory in August 2014. Arnold was approached to switch codes and play Australian rules football in the newly formed AFL Women's in 2016, but chose to remain in soccer. In October 2016, Brisbane Roar announced that they had signed Arnold. In March 2018, she signed with Arna-Bjørnar in the Toppserien. In July 2019, she played for the Chicago Red Stars, in the NWSL. On 9 July 2020, Arnold signed for English club West Ham United of the FA Women's Super League. On 18 April 2021, Arnold was handed a surprise 20-minute cameo in midfield during an 11–0 win over Chichester & Selsey in the fourth round of the Women's FA Cup. International career Arnold received her first call-up to the Australian national team for a tour of the United States in 2012. She made her debut in November that year, keeping a clean sheet in a win over Chinese Taipei in the 2013 EAFF Women's East Asian Cup preliminary round 2. She soon began to feature regularly in national squads in 2013, with previous incumbent goalkeepers Melissa Barbieri and Lydia Williams unavailable. Following their returns, Arnold was not included in the national setup for some time, before returning for the 2015 Cyprus Cup in March 2015. Mackenzie was included as one of three goalkeepers in the Matildas squad for the 2015 FIFA Women's World Cup in Canada. Arnold was selected in the Australia squad for the 2016 Summer Olympics as one of two goalkeepers in the squad along with Lydia Williams. She played one match in the tournament, a group stage win over Zimbabwe. Arnold was