Records show a judge finalized the couple's divorce Nov. 22. The pair entered into a 103-page settlement agreement, but the document will only be filed if the couple has a dispute about it later on.
The filings do not detail custody arrangements for the couple's 3-year-old son, Bronx.
The finalized judgment was first reported Wednesday by celebrity news website TMZ.com.
Simpson is the sister of singer Jessica Simpson. She has released three albums and appeared in a reboot of the TV series "Melrose Place."
Wentz's band, Fall Out Boy, has been on hiatus since 2010. The 32-year-old is currently a member of the band Black Cards.