Wienholt was born in 1918.[3] He was a Queenslander who went into practice with his wife, Hilda Wienholt in Red Hill, Queensland. Hilda died suddenly on 14 September 1944; the couple had a child aged just 11 months at the time of Hilda's death.[4] The doctors who performed Hilda's autopsy were unable to determine the cause of her death.[5][6]
Wienholt began his Australian Public Service career in 1950.[7] He was promoted to Senior Medical Officer, grade 2, third division in 1957.[8]
Between 1968 and 1973 he was a Deputy Director-General at the Department of Health.[3] In January 1973 he was appointed Director-General of the Department of Social Security.[3] During his time as head of social security, Wienholt organized for his desk clerks to attend two-week courses in the slums of Melbourne and Sydney to "sensitise" them to the problems of departmental clients.[9]
Wienholt retired due to ill health early into his term at the Department of Social Security,[10] he had suffered a heart attack in April 1973.[11] He died later that year.[3]