Aussie actor Heath Ledger has become a dad, according to People magazine.

The star's fiancée, Michelle Williams of Dawson's Creek fame, apparently gave birth to a baby girl, Matilda, on Friday.

The couple appear together as husband and wife in soon-to-be-released film Brokeback Mountain, about two cowboys who fall in love with each other.

Ledger's publicist Mara Buxbaum had no comment on the report.