Ashleigh Barty has been crowned the 2021 World Champion of women's tennis, rounding off her impressive year.

This is the second time the Australian has won the award and she retains her title after scooping the award back in 2019. 

The International Tennis Federation (ITF) honoured Barty on Thursday, alongside Novak Djokovic, who has been named the men's world champion.

Barty claims the 2021 award after winning five career titles this year, including her second Grand Slam. 

After 11 months away from the court due to concerns over the Covid-19 pandemic, the world number one returned to to action this year to ensure her spot at the top of the rankings remained secure.

In the lead up to the Australian Open, Barty won the 2021 Yarra Valley Classic in Melbourne, but was left disappointed on the big stage when Karolína Muchová defeated her in the quarter-finals of her home Grand Slam.

Using the defeat as a learning curve, Barty went on to win the Miami Open in April and defend her title. Her victory made her the first number one seed to clinch the title since Serena Williams in 2015.

The Australian triumphed at the Stuttgart Open on her debut at the tournament. This set her up to win the second Grand Slam of her career after defeating Karolína Plíšková to be crowned Wimbledon champion.

Barty's victory made her the first Aussie woman since Evonne Goolagong Cawley in 1980 to lift the title at the All English Club. She dropped just two sets throughout the competition and beat Plíšková 6-3, 6-7, 6-3 in the final.

The world number one rounded off a glittering 2021 by clinching the Cincinnati Open title and her fifth of the year.

"Being the ITF world champion in 2021 is something I am very proud of," Barty said. "I feel fortunate to play the sport I love for a living, especially in a year that was challenging and unpredictable for so many.

"I want to thank my team and my family for everything they do and a huge thank you to tennis fans around the world for continuing to support us."

There was no ITF World Champion award during 2020 due to Covid-19, so Barty enjoys back-to-back honours and joins a star-studded list of multiple-time winners of the award. Steffi Graf holds the record for the most awards won with seven.