Brand filed for divorce from Perry in Los Angeles in December 2011, citing "irreconcilable differences" as the cause of their separation.
The former couple reached a settlement in February, but California required them to wait six months before an official divorce.
Perry and Brand's six-month waiting period expired on Monday (July 16) and now both are legally single again, according to E! News.
Brand has been linked with several woman since splitting from Perry, including painter Oriela Medellin Amieiro, David Hasselhoff's ex-girlfriend Anouska de Georgiou and video presenter Emily Hartridge.
Perry was rumoured to be dating Florence + the Machine's Robert Ackroyd, but she recently insisted that the romance is not "serious".
Brand and Perry were married in October 2010 in Rajasthan, India.
Watch a trailer for Katy Perry: Part of Me below: