The 30-year-old, who was a key part of Australia's impressive Olympic campaign, has signed with Spurs until the end of the 2023 season.
Simon became the first Indigenous player and just the ninth Matildas representative to make 100 appearances for her country as Australia narrowly missed out on a medal with a 4-3 loss to the United States in the bronze medal playoff on Thursday.
"I'm really excited to join Spurs, an incredible, historic club that is known around the world," Simon told the club's official website.
"Playing in the WSL has always been a dream of mine and I'm so happy to be joining such a big club.
"It's a fantastic opportunity and a good challenge for me."
Her move to England comes after a spell with Dutch giants PSV Eindhoven, which included ankle surgery earlier in the year.
Simon is no stranger to injuries; she has overcome a knee reconstruction, two shoulder surgeries and numerous soft tissue tears over her career as well as a devastating ankle injury which forced her to miss the 2019 World Cup in France.
Matildas defender Alanna Kennedy played at Tottenham last season but has since been released.