"I Know Who Killed Me" star Lindsay Lohan celebrated her 23rd birthday by holding a bikini party at Wet Republic at the MGM Grand Resort Hotel & Casino in Las Vegas on Saturday, June 27. She actually will turn to 23 years old on Thursday, July 2.

Lindsay, according to Radar Online, made five outfits changes during the celebrations. At the beginning of the event, she donned a sexy red Herve bandage bikini paired with big sunglasses.

Additionally, she was photographed sporting sexy black bikini. Lindsay then continued wearing a blue blouse matched with black hot pants to dance to Michael Jackson's song. She was also seen striking a King of Pop pose to pay tribute to the 50-year-old singer.

Lindsay Lohan was in Las Vegas to launch her new tanning line, Sevin Nyne, but she managed to turn the event into an early birthday pool party. She invited some of her friends to come to the bash. Unfortunately, her estranged girlfriend Samantha Ronson wasn't seen among the guests.