Joseph T. Leckert, 75, a retired lumber merchant, builder and real estate dealer, died of cancer Feb. 14 at his home in Falls Church.

Mr. Leckert was born in Washington and graduated from McKinley Technical High School. He worked for several lumber compainies in this area until 1944, when he established the Pentagon Lumber Co. He also founded the Dinwiddie Pine Corp. He operated both firms and was engaged in building and real estate until his retirement in 1969.

He was a member of the Northern Virgina Builders Association and the Northern Virginia Apartment Owners Association. He also was a past president of the Washington area chapter of the Hoo Hoo Club, an international fraternal organization of lumbe merchants.

Since his retirement, Mr. Leckert had divided his time between homes in Falls Church and Fort Lauderdale, Fla.

Survivors include his wife, Aubyne O., of the homes; a son, Joseph T. Jr., of Falls Church; three daughters, Mary Ellen Jamison, of Upper Marlboro, Joanne Macleay, of Annandale, and Marion Burton, of Fairfax; a sister, Elsie L. Snider, of Clarksville, Md., and 10 grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the Cancer Home Care Program, Vincent T. Lombardi Cancer Research Center, Georgetown University Hospital, Washington 20007.