Thomas Dempster Clemens, 54, a federal authority on education died Sunday at Sibley Memorial Hospital after a heart attack.

He was division chief of information and communications systems of the National Institution of Education in the Department of Health, Education and Welfare at the time of his death.

Mr. Clemens came to Washington in 1960 to administer federal research grants to the National Institute of Education when it was established in 1972. Both come under HEW.

Born in Venice, III., he grew up in St. Louis, Mo. After serving with the Army infantry in Africa and Italy in World War II, he earned a bachelor's degree from Washington University in St. Louis.

Mr. Clemens then studied at the University of Florence in Italy. He later earned a master's degree at the University of Wisconsin.

From 1950 to 1952, he was audio visual director of the schools in St. Louis, the University of Wisconsin, the University of Florida and San Jose College in California before coming here.

Mr. Clemens was a Brooking fellow in 1968 and 1969. He was a member of the National Association for the Advancement of Science.

He is survived by his wife, janet B., and a son, Matthew D., of the home in Washington, and his mother, Mrs. G.T. Clemens, of St. Louis.

The family suggests that expressions of sympathy may be in the form of contributions to Washington Cathedral.