The 54-year-old actress has been mostly single since divorcing second husband Rhett Hartzog in 2004, and thinks it would be hard to meet someone new because she feels so cut off from the rest of the world.
She told Town & Country magazine: "I'm in an unusual stage right now, because I haven't dated in so long. The sense of isolation turns it all into a bigger deal.
"Just taking the risk of opening that door is really hard for me right now."
MacDowell has adult children Justin, 26, Rainey, 22, and Margaret, 17, with ex-husband Paul Qualley.
The Four Weddings and a Funeral star admits she fantasises about being confident around men.
She continued: "In my fantasy, I would get into elevators, those old-fashioned, really beautiful ones in Paris, and start hitting on men... It didn't matter what they looked like or how old they were... And as soon as the doors would open, it would be over."