| Abbots Trace | 1917 | Pot 8 o's系 |
| Abernant | 1946 | Owen Tudor系 |
| Able Seaman | 1943 | Hyperion系 |
| Above Suspicion | 1956 | Fair Trial系 |
| (アラ) Abu Afas | 1947 | Arab父系 |
| Acatenango | 1982 | Hampton系 |
| Accipiter | 1971 | Teddy系 |
| Acer | 1961 | Owen Tudor系 |
| Ack Ack | 1966 | Himyar系 |
| Acropolis | 1952 | Blenheim系 |
| Admiral Drake | 1931 | King Fergus系 |
| Admiral's Walk | 1936 | Hyperion系 |
| Aethelstan | 1922 | Teddy系 |
| Affirmed | 1975 | Raise a Native系 |
| Aggressor | 1955 | Blandford系 |
| Ahonoora | 1975 | Clarion系 |
| Airborne | 1943 | Hurry On系 |
| Ajax | 1901 | Bend Or系 |
| Akarad | 1978 | Blenheim系 |
| Alarm | 1868 | Pot 8 o's系 |
| Alawa | 1905 | St. Simon系 |
| Alcantara | 1908 | King Fergus系 |
| Alchimist | 1930 | Hampton系 |
| Alcide | 1955 | Blenheim系 |
| Aleconner | 1909 | St. Simon系 |
| Alibhai | 1938 | Hyperion系 |
| Alizier | 1947 | The Tetrarch系 |
| Alleged | 1974 | Ribot系 |
| All Hands | 1957 | Royal Charger系 |
| Al Nasr | 1978 | Lyphard系 | Alsab | 1939 | Himyar系 |
| Alycidon | 1945 | Blenheim系 |
| Alydar | 1975 | Raise a Native系 |
| Alysheba | 1984 | Alydar系 |
| Alzao | 1980 | Lyphard系 | Amadis | 1906 | Pot 8 o's系 |
| Amber | 1942 | King Fergus系 |
| Amberite | 1894 | Pot 8 o's系 |
| Ambertree | 1900 | Pot 8 o's系 |
| Ambiorix | 1946 | Tourbillon系 |
| Ambiopoise | 1958 | Tourbillon系 |
| Amphion | 1886 | King Fergus系 |
| Amsterdam | 1907 | St. Simon系 |
| Androcles | 1870 | Herod系 |
| Angri | 1959 | Dante系 |
| Antonio | 1918 | Pot 8 o's系 |
| A.P. Indy | 1989 | Bold Ruler系 |
| Appiani | 1963 | Son-in-Law系 |
| Arbar | 1844 | Djebel系 |
| Arbitrator | 1874 | Matchem系 |
| Archregent | 1981 | Northern Dancer系 |
| Arctic Prince | 1948 | Prince Rose系 |
| Arctic Star | 1944 | Nearco系 |
| Arctic Tern | 1973 | Native Dancer系 |
| Arden | 1941 | Pharis系 |
| Argosy | 1914 | Bend Or系 |
| Aristophanes | 1948 | Hyperion系 |
| Armageddon | 1949 | Himyar系 |
| Artist's Proof | 1926 | Hampton系 |
| Arts and Letters | 1966 | Ribot系 | Aryshire | 1885 | Hampton系 |
| Assert | 1979 | Northern Dancer系 |
| Asteroid | 1861 | Herod系 |
| Asterus | 1923 | Teddy系 |
| Athanasius | 1931 | Pot 8 o's系 |
| Atlantic | 1871 | Herod系 |
| Aughrim | 1883 | Pot 8 o's系 |
| Aureole | 1950 | Hyperion系 |
| Auriban | 1951 | Pharis系 |
| Australian | 1858 | Matchem系 |
| Australian Sun | 1917 | King Fergus系 |
| Avalanche | 1942 | Hurry On系 |
| Avatar | 1972 | Ribot系 |
| Avington | 1890 | Pot 8 o's系 |
| Awesome Again | 1994 | Northern Dancer系 |