The Mean Girls star was arrested last month for driving her car while intoxicated when she crashed into a curb in Beverly Hills. She has since re-entered a detoxification centre.
Lohan decided to cancel her birthday party, which would have taken place in Las Vegas at the nightclub Pure.
A spokesperson for the actress told FemaleFirst, "The party was cancelled officially over two weeks ago. We were confused why Pure was even still promoting it. But Lindsay will not be having the birthday party at Pure and is focusing on her recovery 100 per cent."