The Annie Automatic musician reportedly proposed to Tisdale Thursday evening atop the Empire State Building in New York, People magazine said Friday.
"Best night of my life. We're on top of the world," the "High School Musical" actress tweeted Thursday.
The pair began dating publicly in December 2012, People said.
Tisdale told Maxim magazine she likes "the dark, mysterious bad boy" and considers herself "old-school when it comes to dating."