The pair first met while Lachey was shooting the video for his song 'What’s Left Of Me' following his divorce from Jessica Simpson. Minnillo, 28, had just split from New York Yankees star Derek Jeter.
The couple "have amicably split but remain good friends who still greatly care for one another", Minnillo's publicist told E!.
The former MTV VJ, 28, was spotted in Los Angeles last night out with a group of girlfriends.
Lachey recently came to ex-wife Simpson’s defence after she was scrutinised in the media over her weight-gain.