Weepu tweeted about his new contract with the Auckland franchise on Saturday, saying: "It's official ... sign, sealed, delivered! Stay with the Blues next season. Happy."
He will join close friend Ma'a Nonu in working with new coach Sir John Kirwan after Pat Lam's contract wasn't renewed following a dismal 2012 campaign.
After signing from the Hurricanes on a one-year deal, Weepu struggled with weight and form issues but turned those around to finish the competition strongly.
The re-signing follows rumours he was homesick for Wellington.
Kirwan told Fairfax Media he was excited about having two key All Blacks in his squad.
"They (Weepu and Nonu) are two X-factor players and I'm really glad they are here," said Kirwan.