Alisal wildfire has now burned more than 16,800 acres in Santa Barbara County
Pitt, 57, bought the $5.5m property in Goleta, near Santa Barbara, in 2000, but now officials have included it the evacuation warning zone as firefighters battle the blaze.
The wildfire started on Monday in the Santa Ynez Mountains and has now burned its way south over 16,800 acres to the ocean.
The fire was just five per cent contained on Wednesday night.
Residents in the evacuation area are either in the red mandatory orders zone and must leave immediately, or the yellow warning zone, that advises them to leave.
Strong and shifting winds from the north have fanned the fire, forcing the closure of the 101 freeway in western Santa Barbara County.
The highway could remain shut until the weekend says the US Forest Service.
Mandatory evacuation orders are in place in Arroyo Hondo Canyon, Refugio Canyon, and the area between El Capitán State Beach and West Camino Cielo.
Fire crews have also been protecting Rancho del Cielo, which was once owned by Ronald and Nancy Reagan and was known as the Western White House during his presidency.
Officials say that area has not burned since 1955.
“We are thankful that there has been no fire activity on the actual Reagan Ranch property. The Ranch, self, is still in a very defensible position,” said Jessica Jensen, vice president and chief of staff of the Young America’s Foundation, which now operates the ranch.
California wildfires have scorched nearly 3,900 square miles this year and destroyed more than 3,600 huise, businesses and other structures, according to the state Department of Forestry.