Duff began dating singer Aaron Carter in 2001. They met on the sets of Lizzie McGuire, during Carter's guest appearance in a Christmas episode. The relationship lasted two years. It was reported that Carter left Duff for Lindsay Lohan, but soon broke up with Lohan and resumed dating Duff. Carter later stated that he also cheated on Duff with her best friend, and that Duff "got her heart broken" and he was "sorry" for his actions. On March 23, 2007, Claymation facsimiles of Duff and Lohan appeared on the celebrity wrestling series Celebrity Death Match episode "Where's Lohan?". Duff and Lindsay Lohan were later reported to have been involved in a "feud" with each other over their relationship with Carter. In 2007, Duff and Lohan had reconciled. Lohan attended the release party for Duff's album Dignity and Duff told People magazine that she thought Lohan was "fun" and "a nice girl".

In 2004 Duff began dating Good Charlotte singer Joel Madden. After a long period of tabloid spec