Frederick W. Marshall Jr., a former supervisor in the personnel department at Social Security Administration headquarters in Woodlawn, died Sunday after a heart attack while visiting his daughter in Ellicott City.

Services were being held today at the Harry H. Witzke funeral establishment, 4112 Old Columbia Pike in Ellicott City.

Mr. Marshall, who was 75, moved to Melbourne, Fla., after his retirement in 1977.

He is survived by his wife, the former Margaret Neary; a son, Frederick W. Marshall 3rd of Panama City, Fla.; a daughter, Kathleen Marshall Adams of Ellicott City; two sisters, Trudy Raffin of Beverly Hills, Calif., and Dorothy Varipapa of West Hempstead, N.Y.; and two grandsons.