The deal is for one season but the Reds have an option for a second.
Henrique departed Brisbane at the end of last season after playing 136 times for the three-time champions over eight seasons, helping Roar clinch A-League championships in 2010-2011, 2011-2012 and 2013-2014.
Scoring 39 goals for Brisbane during his time in Queensland, Henrique was twice the difference for the club when it mattered most, netting the winners in the 2011 and 2014 grand finals.
Henrique, 31, joins the Reds ahead of 2016-2017 with a wealth of experience in the A-League.
Henrique said he is excited to join the A-League champions and is looking forward to the hard work that comes with mounting a championship defence.
“I feel great to have signed for Adelaide United and I’m very excited for this new challenge,” Henrique said. “It’s such a great club who have just become champions of the A-League.
“The coaching staff and the players are all great and I’m really looking forward to joining up with my new teammates in Malaysia and getting ready for the new season.
“I’ve been part of a championship-winning team before and I know how hard it is to defend that title. So I know we will need to work hard to keep up a standard where we can push to go back-to-back.
“When I was with Brisbane, I remember that it was always very difficult to play against Adelaide, especially at Coopers Stadium with all the great support from the fans.
“Now I am excited for all the supporters to be supporting me for a change, and of course the team as well.
“I have a fair bit of experience in the A-League so I think that can be helpful with the team and some of the younger players.
“But on a personal level, I am here to score as many goals as I can and to be better than I was last season.”
Adelaide United coach Guillermo Amor said he was delighted to add another experienced forward to his squad.
“Henrique is a very good player and someone we think can add very good things to our team,” Amor said.
“He has played in the A-League for many years and knows the competition in and out.
“As a forward he can score lots of goals and he has proved to be a very dangerous player against many teams.
“I am sure he will fit in well to our team and he will help improve our football.”
Henrique will link up with his new teammates on Adelaide’s pre-season trip to Malaysia.