Billings became the first men's player to sign for the BBL under the league's new multi-year contract option for overseas players.
Under the terms of such contracts, players must commit to see out the full season, rather than leave early or arrive late to link up with rival T20 leagues.
Billings, who last featured for England in 2022, has declared he will be with the Thunder for the entire campaign during each year of his contract.
It's a big boost for the Thunder, who managed only one win last season on the way to the wooden spoon.
Locked in Thunder green until the end of BBL|16🔒— Sydney Thunder (@ThunderBBL) #ThunderNation ⚡� pic.twitter.com/JMPzzVWL5AJune 12, 2024
"On the field we are pulling together a really good squad and the chance to work with such an accomplished coach as Trevor Bayliss again was very appealing," Billings said in a statement.
"The BBL is in such a great place these days, it's well run, well supported and definitely the best tournament in the world staged at that time of the year.
"That's why I have committed long term and to be here right until the end of the tournament each year.
"At this stage of my career and life, where I play, the people I play with and the community I am part of is really important to my family and I and I know Sydney Thunder provides me with the best opportunity to enjoy my time and play some really good cricket."
Billings first joined the Thunder in 2020 before switching to Brisbane Heat after two seasons.
The 32-year-old has played three Tests, 28 ODIs and 37 T20Is for England.
The BBL will announce the order for the overseas draft on Thursday evening.
Picks from one to four will be drawn from teams that did not participate in last season's finals.
It means the teams who made the finals - the Heat, Sydney Sixers, Perth Scorchers and Adelaide Strikers - can only hope for pick No.5 at best.
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