The actress, 30, cited irreconcilable differences when she filed the petition on Monday, according to TMZ.
Amber, who first started dating Johnny in 2012 is said to be seeking spousal support.
Sources tell the website the couple had no prenuptial agreement in place before they tied the knot.
Johnny - who is estimated to be worth around $400 million - is now said to have filed a response through his lawyer Laura Wasser asking for Amber's claim for spousal support to be turned down.
Amber filed for divorce just two days after Johnny’s mum Betty Sue Palmer passed away.
Johnny split from French actress Vanessa Paradis in 2012 after 14 years together.
