S. Harold Williams, 75, a retired vice president of Merrill Lynch, Pierce, Fenner & Smith, investment banking and brokerage firm, died Friday of a heart attack while on the golf course of the Chevy Chase Club.

He had retired in 1969 after more than 30 years with Merrill Lynch and 42 years in the brokerage business.

Mr. Williams was born in Lebanon, Ohio. He graudated from Ohio University and came here in 1926 to enter George Washington University Law School, where he also graduated.

He became a bond salesman, later joining Fenner & Beane. He went with the firm when it merged with Merrill Lynch, E. A. Pierce & Cassatt in 1941.

Appointed assistant manager of the Washington office, Mr. Williams later became manager of a second office on K Street NW in 1956. He was elected a vice president in 1965.

Mr. Williams was a member of the Chevy Chase Club and St. John's Episcopal Church in Chevy Chase. He had won several amateur golfing awards.

He is survived by his wife, Pauline, of the home in Washington; a son, Harold, of Warwick, N.Y., a daugther, Paula Fangboner, of Olney, and two grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the Episcopal Center for Children in Washington.