Penn is dating charity's former PR guru

Actor Sean Penn's mystery woman has been identified - she's the former communications boss of his charitable organization for Haiti.

The star was spotted with the beauty back in July (11), just weeks after his reported romance with Scarlett Johansson came to an end.

The pretty brunette has now been named as Shannon Costello, the ex-communications director of the actor's J/P Haitian Relief Organization, which helps those affected by the nation's devastating 2010 earthquake.

According to People.com, Costello is now a producer, and will be working on Ron Howard's upcoming project Under The Banner of Heaven.

And the pair looked close as they held hands heading to a Miami, Florida restaurant on Friday (19Aug11).

Penn divorced longtime wife Robin Wright last year (10).