The talented 24-year-old, a former Australian age-group representative player, has previously been contracted to the Waratahs and was in the Melbourne Rebels wider training squad.
Blessed with speed and a strong pass, the Wellington-born scrum half came to prominence in the 2012 season with the Tasman Makos in the ITM Cup.
This season Sua, who featured at the 2011 Rugby World Cup,has challenged experienced Crusaders duo Andy Ellis and Willi Heinz for the halfback role.
Director of Rugby Dean Ryan is delighted that Su'a will make the move from New Zealand and battle for the No.9 shirt this season with Jonny Arr and Paul Hodgson.
And speaking to www.warriors.co.uk, the Samoan scrum half has revealed he is determined to make the move to England a big success.
"I'm very happy with my decision to move to Worcester and become a Warrior," said Su'a, who will join up with his new team-mates next month.
"It's an exciting opportunity for me to experience how rugby is played in the Northern Hemisphere and that will be hugely beneficial to my game.
"I'm looking forward to the challenges ahead and linking up with my international team-mate David Lemi and the boys at Worcester.
"I've heard very good things are about the club and I see it as a great environment to further progress my rugby."
Watch new signing Jeremy Su'a in action here HERE for Samoa!
Join Su'a and the Warriors at Sixways next season! Season Tickets available NOW! Call the Warriors Box Office on 01905 454183 or click HERE to buy online.