The 27-year-old actor took to his Twitter account to mark their anniversary with a special photo and note.
“Happy anniversary baby :) I love you. September 5th @SamiMiro,” Zac wrote with a photo of their reflection in a window.
“Time flies when you’re having fun. Happy anniversary baby. I love you too. September 5th @ZacEfron,” Sami replied with another new photo of the couple.
Zac and Sami made their first appearance as a couple on the red carpet just a few weeks ago at the We Are Your Friends premiere.
Click through the gallery below for lots of their social media pics…