"Best night of my life. We're on top of the world," Tisdale tweeted after French proposed on the 103rd floor of the Empire State Building in New York City on Thursday, Aug. 8.
"He had been planning on it for awhile. I think she knew it was coming but she is so happy," a source says of the engagement.
Tisdale, 28, and French first went public with their relationship in December 2012 while visiting an Apple store in L.A. "She likes those rocker types," a source told Us at the time. "They have mutual friends and just met through hanging out."
The former High School Musical actress previously dated Step Up Revolution director Scott Speer until their split in December 2011. She also briefly romanced Boys Like Girls musician Martin Johnson.