Isabelle Maree Kelly (born 20 September 1996) is an Australian rugby league footballer who captains the Sydney Roosters in the NRL Women's Premiership.

Primarily a centre, she is an Australian and New South Wales representative.

Born in Gosford, New South Wales, Kelly played her junior rugby league for the Berkeley Vale Panthers. Her father, Ken, played for the Manly Warringah Sea Eagles in the 1980s, while her brother, Dylan, played for Manly's under-20'sand NSW Cup, played for Burleigh Bears Queensland Cup and represented his state in the NSW Blues resident squad in 2016.

In 2015, Kelly made her debut for New South Wales, scoring their only try in a 4–all draw with Queensland.

In 2017, she was a member of the Jillaroos 2017 Women's Rugby League World Cup winning side, scoring the first try in the final against New Zealand.

In June 2018, Kelly was announced as one of fifteen marquee signings by the Sydney Roosters Women's team which will participate in the inaugural NRL Women's Premiership in September 2018.

On 22 June 2018, Kelly scored two tries for New South Wales in their Women's State of Origin win over Queensland and was awarded the Nellie Doherty Medal for Player of the Match.

In Round 1 of the 2018 NRL Women's Premiership, Kelly made her debut for the Sydney Roosters, starting at centre and scoring her side's only try in their 10–4 loss to the New Zealand Warriors.