Zellweger donned a fat suit a la Bridget Jones and rode in the parade through Harvard Square hamming it up with the team's cross-dressing crew.
"This is the nicest doorstop I've ever had," Zellweger says during the award ceremony.
"I have always had great faith that no matter the state of the union, that America's future was sound so long as Harvard continued to deliver us her brightest and best. And after what I have experienced and witnessed today, I can tell you that I'm going to really have to re-think all that."
The award honors performers who have made a lasting contribution to the entertainment world.
Previous honorees have included Halle Berry, Charlize Theron, Katharine Hepburn and Meryl Streep.
Next week's Man of the Year award will go to actor James Franco.
Zellweger is currently starring in the romantic comedy New in Town.
And you'll see personalized content just for you whenever you click the My Feed .
SheKnows is making some changes!