A gunman has opened fire in a central Florida beauty salon, fatally shooting three women and wounding a fourth before leaving the scene and killing himself, police say.

The gunman entered Las Dominicanas M & M Salon in Casselberry shortly after 11am on Thursday, police spokeswoman Sara Brady said. Two women escaped the salon.

Brady said the shooting appeared to be part of a domestic dispute.

The gunman, identified by police as Bradford Baumet, was served with a domestic violence injunction October 9 and scheduled to be in court on Thursday for a hearing with the salon's manager, Marcia Santiago, who took out the restraining order. Their relationship was not immediately clear.

Police have not identified the victims, and it was not clear whether Santiago was at the salon.

Brady said the fourth victim was being treated at an Orlando hospital. Her condition was not immediately released. Casselberry is about 24km northeast of Orlando.

After the shooting, the gunman went to a friend's home nearby and shot himself, said Seminole County Sheriff's Office spokeswoman Heather Smith. He did not threaten his friends, but said "he had some problems, problems he could not remedy".

A witness told the Orlando Sentinel he heard gunshots before seeing the gunman take off.

"We saw the guy with the gun in his hand ... coming this way ... on foot with the gun in his hand,'' said Juan Diaz, who was at a nearby store at the time of the shooting.

He said he went into the salon once the gunman left and saw "a bunch of dead bodies'".