Former Owner
- Apostolo Zeno1
- Appiano family1
- Archer Milton Huntington1
- Archibald Cary Coolidge1
- Archibald Primrose, 5th Earl of Rosebery1
- Arenburg1
- Arno M. Voynich1
- Arnold Jansen op de Haar1
- Arnold Mettler4
- Art ancien S.A.6
- Artemesia Piccolomini1
- Arthur Annesley, 1st Earl of Anglesey1
- Arthur Brölemann3
- Arthur Griffith1
- Arthur H. Lea4
- Arthur Haddaway1
- Arthur Hood, 1st Baron Hood of Avalon1
- Arthur Lee Loeb1
- Arthur Liddell, 5th Baron Ravensworth1
- Arthur M. Ellis1