Lydia Grace Yilkari Williams (Aboriginal pronunciation: [jɪlkɑɹiː]; born 13 May 1988) is an Australian professional soccer player who plays as a goalkeeper for A-League Women club Melbourne Victory.

Williams previously played for Melbourne City and Canberra United in Australia's W-League; Reign FC, Houston Dash and the Western New York Flash in the National Women's Soccer League (NWSL) in the United States; Piteå IF in Sweden's Damallsvenskan; and Arsenal in England's FA Women's Super League (WSL).

Inducted to the Aboriginal and Islander Sports Hall of Fame, she earned for her first cap for the Australian national team, commonly known as the Matildas, at age 16.

!, which drew on her life experiences, from growing up in the desert to achieving success as an Aboriginal female football player.

[13] After advancing to the Playoffs, they faced Brisbane Roar in the semi-finals and tied 2–2 leading to a penalty kick shootout in which Canberra lost 2–4.

[14] In 2014, the Western New York Flash signed Williams to be their starting goalkeeper following a season-ending injury to Adrianna Franch.

She recorded two shutouts in 2014 prior to suffering a season-ending ACL injury while competing at the 2014 AFC Women's Asian Cup with the Australian national team.

She was the starting goalkeeper in the 10 games in which she played and helped Canberra finish second in the regular season with a 8–2–2 record, earning a berth to the Playoffs.

[23] Williams was the starting goalkeeper in 15 games helping Melbourne City finish in fourth place during the regular season with a 6–4–2 record, securing a berth to the Finals.

[27] Returning to Houston for the 2017 season, Williams made 8 starts in goal before being traded to Seattle Reign FC on August 31 in exchange for a 2018 2nd-round draft pick.

[31] After defeating the regular season premiers, Brisbane Roar, in a 2–0 shutout in the semi-final,[32] Melbourne City faced Sydney FC in the Grand Final and won 2–0, clinching the team's third consecutive title.

[34] The third-place finished earned the team a berth to the Playoffs, though they were defeated 2–1 by local rivals Portland Thorns FC in the semi-finals.

[39] During the playoffs, Williams helped elevate City to a 5–1 win in the team's semi-final match against Western Sydney Wanderers.

[43] On 18 November 2020 Williams made her debut as she started in the FA Women's League Cup against North London derby rivals Tottenham Hotspur.

On 21 July 2022, Division 1 Féminine club Paris Saint-Germain announced the signing of Williams on a one-year deal until June 2023.

[49][50] At age 19, Williams was selected to the Matildas squad for the 2007 FIFA Women's World Cup in China, though she did not play.

[52] She shared the starting goalkeeper role with veteran Matilda Melissa Barbieri at the 2011 FIFA Women's World Cup in Germany.

[61] In the 90th minute, Williams stopped Christiane's header marking 10th-ranked Australia's first win against Brazil in World Cup history.

[63] After qualifying for the 2016 Rio Olympics in Japan, the Matildas faced Canada in their first group stage match with Williams in goal.

[67] During the team's first group stage match against Italy, a late Italian goal in the 5th minute of extratime resulted in a 2–1 surprising loss for the Matildas.