Actress Sandy Duncan and her husband, Halstead’s Don Correia, got married on the grand terrace of this Upper East Side penthouse, at 139 E. 79th St., in June 1980.

They bought the spread for around $350,000 in 1978 (when it was a rundown estate-sale purchase) and sold it for $1.1 million in 1983 after overseeing a major renovation.

At the time, Duncan was pregnant with their second child, and the family needed more space.

Now, 36 years later, the penthouse is back on the market — and Correia is marketing it alongside Judy Oston.

The two-bedroom, three-bathroom unit is asking $2.8 million.

This home runs a full floor, and opens with a private elevator landing that leads to a gallery, which opens to the living room.

The living room comes with an original English stone woodburning fireplace and French oak doors with leaded glass from Frank Lloyd Wright’s original Francis W. Little house in Minnesota.

There’s also a formal dining room and a renovated kitchen with a skylight.

And as for that terrace where Duncan and Correia were married, it’s nearly 1,400 square feet and has southern, eastern and some northern exposures.