Aminoff was born on 4 April 1897 in Stockholm, Sweden, son of the cabinet chamberlain Gregor Aminoff and his wife Elisabeth (née af Edholm).

He served as ryttmästare in the Life Regiment of Horse (K 1) in 1934 and received a Bachelor of Arts degree in 1925.

[1] Aminoff became an attaché at the Ministry for Foreign Affairs in Stockholm in 1926.

He served as chamberlain of the Duke and Duchess of Västergotland from 1935 to 1950, and he was back at the Foreign Ministry in 1938.

He was Marshal of the Diplomatic Corps (Introduktör av främmande sändebud) from 1970 to 1974 (deputy in 1966) and Grand Master of the Ceremonies from 1971 to 1977.