The robbery happened at about 6:30 a.m. at a home in the 1400 block of Matthew Drive, police said.
A 49-year-old woman was in her garage at the time, loading items into her car when two gunmen wearing ski masks approached her, police said.
One of the suspects held the victim at gunpoint while the other suspect entered her house and confronted her 53-year-old husband at gunpoint, ordering him to open a safe, police said.
The suspects fled from the house with an undisclosed amount of cash and police were unable to locate them after searching the neighborhood. No vehicle was seen or heard, police said.
Neither victim was injured.
The suspects were described as wearing light-colored sweatshirts and ski masks and each armed with a handgun.
Anyone with information is asked to call the Fairfield Police Department at (707) 428-7300 or Solano Crime Stoppers at (707) 664-STOP. A reward up to $1,000 is being offered for information leading to the arrest of the suspects.