Rainbow Six Siege now has more than 30 million registered across PlayStation, Xbox and PC.
Ubisoft's multiplayer shooter launched in December 2015, and it has been steadily growing in popularity ever since.
In August last year it reached 20 million players, with 2.3 million daily active users. Four months later, on its second anniversary, it had 25 million registered users, and it has added another five million in the four months since then.
"Over the last three years we have endeavoured to create a solid community built on transparency as we grow and evolve the ever-expanding world of Rainbow Six Siege," said Alexandre Remy, the brand director for Rainbow Six Siege, in a statement.
Ubisoft has also been developing the game as an esport, and its 2018 Six Invitational was both its largest major esports championship to date and a record-breaker in terms of concurrent viewers: 321,000 at its peak.
While Rainbow Six Siege is a premium product, it has had a number of free weekends since it launched, all of which will have contributed to that 30 million total.
Ubisoft was recently forced to withdraw what amounted to a $20 price increase for the entry-level version, amidst complaints from the game's community. However, the Gold Edition and Complete Edition both increased in price by $20 each.