Already signed through 2025, Rachele's new deal ties him to the Crows until the end of the 2029 season.
The 20-year-old follows young teammates Jake Soligo, Chayce Jones, Max Michalanney and Harry Schoenberg in announcing fresh contracts in the past week.
Victoria-born Rachele was pick six at the 2021 national draft and has played 26 AFL games in his first two seasons.
"I'm really happy with where the club is heading," Rachele said in a statement on Wednesday.
"That shows with the number of signings we've announced in the last couple of weeks.
"The club has been really good with my family and I have enjoyed my time here so much, I had no intentions of going home at all."
Adelaide's list manager Justin Reid said Rachele's new deal was a coup for the Crows.
"We've all seen the class that Josh brings to our team," Reid said.
"He is a constant threat around goal when he's playing forward and has shown his ball-winning ability in the midfield as well as a strong defensive mindset to pressure and tackle the opposition.
"As impressive as he has been in his first two seasons, there is still a lot of growth to come in his game and we are thrilled that it will continue to be in a Crows guernsey."