Gordon made his name with some bright performances for the Melbourne Rebels and was the only flyhalf named in Eddie Jones' Wallabies squad for the calamitous 2023 World Cup campaign.
Chastened by that experience, Gordon defected to the 13-man code only for a rare spinal injury to restrict him to just one NRL game at the end of the recently concluded season.
"I'm stoked to return to the game I grew up playing and loving as a kid, especially with the opportunity to represent the team I grew up supporting," the 24-year-old Queenslander said in a statement.
"I've watched both Queensland and the Wallabies from afar over the past year or so, and the journey they're on motivates me to want to work hard and contribute positively on and off the field."
Gordon's return is good news for the revived Wallabies ahead of the 2027 World Cup on home soil, with flyhalf one of the few positions where Australia does not have great depth.
Tom Lynagh, who also plays at the Reds, started the three British & Irish Lions tests this year but, still only 22, lacks a bit in physicality.
James O'Connor and Tane Edmed started tests in the Rugby Championship but the former is 35 and the latter's inexperience at the top level was exposed in some of his decision making and execution.
Ben Donaldson, who was named as a fullback but backed up Gordon at the last World Cup, was named in the Australia A squad for the end-of-year tour last week.
Gordon, who won eight caps in 2023, was notable for both his strong defence and his willingness to take the ball to the line in attack.
The Titans said Rugby Australia had made a "comprehensive financial settlement" to get Gordon out of the second year of his NRL contract.
"Rugby Australia has taken a strategic approach to player contracting this World Cup cycle and we are delighted to bring Carter back into the system," said RA chief executive Phil Waugh.