The left-handed top order batsman, who can also wicket-keep, will be available for the entire season unless called into any Ashes or English Lions tours during the summer.
Duckett, 26, was a member of the 2017-18 Ashes squad and has tasted Test, ODI and T20 International cricket so far in his career.
Duckett will play his first summer in the BBL with the Heat after previously being a touring overseas player for the Hobart Hurricanes when they played a series of off-season development games in the Middle East in 2018.
Duckett said he was thrilled to be a part of a such an important element of the Australian summer.
“I’m extremely excited to be joining the Brisbane Heat for the 2021-2022 Big Bash League,’’ he said.
“I know friends and colleagues have told me what a great team environment it is and how passionate the fans are at the Gabba and on the Gold Coast, and I can’t wait to experience this all for myself.”
“I’m looking forward to getting out to Brisbane and hopefully helping the team have a great season!”
Brisbane Heat head coach Wade Seccombe said Duckett came with strong credentials.
“Ben fits the bill for the type of player we were looking to inject into the Heat squad this season and we’re excited to welcome him to Brisbane. He brings something a little different to what we have had in the squad, being a left-hander who also bats in the top order,’’ he said.
“He has played a lot of first class, List A cricket and T20 in England despite being a relatively young man and enjoyed a significant deal of success along the way. We’re looking forward to further tapping into that potential to give us an important addition to our line-up,” Seccombe said.
Duckett has played 129 career T20 matches, including for the Welsh Fire in the recently completed inaugural staging of The Hundred in the UK, and other stints in the South Africa MSL and Pakistan Super League. He boasts a career strike-rate of 135.56.