The England Saxons player made his final appearance for Bristol last weekend in a 26-16 win over Birmingham Solihull and reported for training with Leeds Carnegie on Monday morning having passed a medical.
Commenting on the signing, Director of Rugby Andy Key said, "We are pleased to have agreed a deal with Adrian to bring him to Leeds Carnegie until the end of the season. Throughout the season, we have identified that fly half and goal kicker are two key areas for us that we do not have the same level of cover as other positions within our squad in terms of senior players. Adrian has a great deal of experience from his time at Bristol and Harlequins and will give us strength in depth in that position as we face a vital run of games in the Aviva Premiership."
Jarvis commented, "When the chance came up to sign for Leeds Carnegie it was an offer that I could not refuse. At 27, I could not really turn down the opportunity to play Premiership rugby again and I am very excited to be part of the group and hopefully I can do whatever the club need of me to help Leeds climb up the table."