The 25-year old New Zealand international, who scored 16 goals for the Nix this season, will spend the next few months with the Reds under former All Whites teammate Ryan Nelsen.
"We're excited to have Jeremy join us on loan. Ryan has played with him on the All Whites and speaks very highly of him," said Toronto FC President and General Manager Kevin Payne.
"He'll provide another option in an attacking position and if he can continue his form from the last A-League season we'll be happy indeed."
Wellington's general manager David Dome added: "It is a great opportunity for Jeremy as the MLS is of a good standard, and it is possible that Jeremy could come back an even better player than he now is.
"The break between seasons in the A-League is too long and the club has been looking for opportunities for some of the players to play football in other leagues in an effort to get greater benefit from the break."