Former Owner
- Antony Bek1
- Apostolo Zeno1
- Appiano family1
- Archer Milton Huntington1
- Archibald Cary Coolidge1
- Archibald Primrose, 5th Earl of Rosebery1
- Arenburg2
- Ariel Toaff1
- Arno M. Voynich1
- Arnold Jansen op de Haar1
- Arnold Mettler4
- Art ancien S.A.8
- Artemesia Piccolomini1
- Arthur Annesley, 1st Earl of Anglesey1
- Arthur Brölemann4
- Arthur Griffith1
- Arthur H. Lea4
- Arthur Haddaway1
- Arthur Hood, 1st Baron Hood of Avalon1
- Arthur Kay1