Katy Perry and J. Molinari Jewelry co-hosted the 1OAK Nightclub Las Vegas grand opening weekend and GiveLove event on Friday night.  The pop star looked like she was having a great time, posing for photos in a sexy blue dress with blue hair.

Katy took to Twitter to thank all of the guests for turning out, writing, "Thanks to everyone who helped out w/ (with) the Give Love event at Mirage & 1 Oak LV. Go to Givelove.org to see how u can make a difference!"

Her ex Russell Brand filed for divorce from Katy on December 30. Both seemed to have swiftly moved on. The actor moved into a new home in Los Angeles just weeks after splitting with the singer.

Last week Katy returned to the stage in Indonesia for her first concert since the break up. The two were married for just 14 months.