Mackenzie Elizabeth Arnold is an Australian professional soccer player. She plays as a goalkeeper for Women's Super League club West Ham United, where she is team captain, and for the Australia national team. 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.

The Australia women's national soccer team is overseen by the governing body for soccer in Australia, Football Australia, which is currently a member of the Asian Football Confederation (AFC) and the regional ASEAN Football Federation (AFF) since leaving the Oceania Football Confederation (OFC) in 2006. The team's official nickname is "the Matildas" ; they were known as the "Female Socceroos" before 1995.