Singer Ashlee Simpson and husband, musician Pete Wentz, arrive at the 30th anniversary of "Star Wars: Episode V The Empire Strikes Back" screening in Hollywood in this May 19, 2010 file photo.[Photo/Agencies]

Singer Ashlee Simpson and husband, musician Pete Wentz, arrive at the 30th anniversary of "Star Wars: Episode V The Empire Strikes Back" screening in Hollywood in this May 19, 2010 file photo.[Photo/Agencies]

Singer and actress Ashlee Simpson filed for divorce on Wednesday from her rock star husband Pete Wentz after less than three years of marriage, according to court documents.

Simpson, 26, the younger sister of Jessica Simpson and a former actress on TV show "Melrose Place", cited irreconcilable differences for the split with Wentz, 31, a musician in the U.S. band Fall Out Boy.

The couple married in May 2008 and have a two year-old son Bronx Mowgli. No date of their separation was given in documents filed with Los Angeles Superior Court and first obtained by celebrity website TMZ.com.

Simpson had hits in 2004 with "Pieces of Me" and her debut album "Autobiography" and appeared in the Broadway musical "Chicago" in 2010.

Wentz and his Fall Out Boy band members put the band on hiatus in 2009 and Wentz has since formed a new project called Black Cards.