The former Bristol and London Wasps speedster, who has featured in the last two Rugby World Cups for his country, has a fantastic pedigree in the English top-flight having scored an impressive 36 tries in 95 games.
Head Coach Richard Hill said: "David is a try scorer and in today's game, when defences are tight and it can be hard to manufacture tries, many come down to individual brilliance. David is the kind of player that makes things happen, a match winner and do things others do not expect.
"His ability from playing sevens means he has the ability to kick and chase at the right time and has a great side step. He brings something different to the game and poses a challenge for defenders.
"David also has an excellent work ethic and will fit into the culture at the club and be determined to make a big impression at Warriors. We look forward to welcoming him from next season."
Lemi was an established figure on the IRB 7s circuit when he first captured the eye of current Worcester Head Coach Richard Hill during the 2005 Safari Sevens in Kenya and later joined Bristol.
The electric back quickly impressed in the 2005/o6 season and scored eight tries in 12 appearances,finishing runner-up in the Premiership try scoring charts in his debut yearas he became a firm favourite at the Memorial Stadium.
Renowned for his pace, Lemi has won a host of accolades for spectacular individual scores and finished as the top scorer in the league in the 2006/07 season. He also finished joint second top try scorer in the 2008/09, when he also won The Sunday Times Try of the Season Award for the try he scored against Bath Rugby in the first game of the season.
Lemi said: "I'm really looking forward to the move to Worcester; it is a fantastic and big challenge for me to move to a club with such ambition as the Warriors.
"I always enjoyed the style of rugby and what I achieved at Bristol under the leadership of Richard Hill and the chance to work with him again is a huge incentive for me.
"Worcester have some very talented young and up-and-coming players at the club and the challenge for me will be to show that I am worthy of a place in the team and also use my experience to be successful at Sixways.
"I would like to thank Scottish Rugby and Glasgow Warriors for the wonderful opportunity I've been given this season. I've really enjoyed my time in Glasgow as part of a fantastic squad of players under a strong management team. We are in a good position in the RaboDirect PRO12, and I remain totally committed to helping Glasgow reach the play-offs and make this season a successful one before I head to Worcester."