|Reference style||His Eminence|
|Spoken style||Your Eminence|
Domenico Mariani (3 April 1863 – 23 April 1939) was a Cardinal of the Roman Catholic Church and was President of the Administration of the Patrimony of the Apostolic See.
Domenico Mariani was born in Posta, Italy. He was educated at the Lyceum "Angelo Mai", Rome and later at the Pontifical Roman Seminary, Rome. He was ordained on 18 December 1886 and began pastoral work in Diocese of Rome until 1900. He was Canon of the Vatican Basilica until 1917 and was created Privy Chamberlain of His Holiness on 30 September 1914. He served as Secretary of the Cardinalitial Commission for the Administration of the Properties of the Holy See from 1917. He was raised to the level of Domestic Prelate of His Holiness on 26 January 1917.
He was created and proclaimed Cardinal-Deacon of S. Cesareo in Palatio in the consistory of 16 December 1935 by Pope Pius XI. Two days later he was named President of the Administration of the Property of the Holy See, that has since been renamed the Administration of the Patrimony of the Apostolic See. He took part in the conclave of 1939 that elected Pope Pius XII. He died in April 1939 and is buried in the Campo Verano cemetery.
| President of the Administration of the Patrimony of the Apostolic See
21 December 1935 – 23 April 1939
Amleto Giovanni Cicognani