| Rabelais | 1900 | St. Simon系 |
| Radium | 1903 | Bend Or系 |
| Ragusa | 1960 | Ribot系 |
| Rahy | 1985 | Red God系 |
| Rainbow Quest | 1981 | Red God系 |
| Raise a Native | 1961 | Native Dancer系 |
| Raja Baba | 1968 | Bold Ruler系 |
| Rapallo | 1894 | Bend Or系 |
| Rataplan | 1850 | Pot 8 o's系 |
| Ravensbury | 1890 | Pot 8 o's系 |
| Reading | 1936 | Pot 8 o's系 |
| Red God | 1954 | Nasrullah系 |
| Redoute's Choice | 1996 | Danzig系 |
| Red Ransom | 1987 | Roberto系 |
| Red Regent | 1972 | Owen Tudor系 |
| Reform | 1964 | Fair Trial系 |
| Relaunch | 1976 | Intent系 |
| Relic | 1945 | Man o'War系 |
| Relko | 1960 | Teddy系 |
| Revenue | 1843 | Eclipse系 |
| Rhodes Scholar | 1933 | Pharos系 |
| Rialto | 1923 | St. Simon系 |
| Ribot | 1952 | St. Simon系 |
| Right Boy | 1954 | Hyperion系 |
| Right Count | 1925 | King Fergus系 |
| Right Royal | 1958 | Owen Tudor系 |
| Rionscup | 1923 | Teddy系 |
| Risen Star | 1985 | Bold Ruler系 |
| Riverman | 1969 | Never Bend系 |
| Roanoke | 1987 | Ribot系 | Roberto | 1966 | Hail to Reason系 |
| Rockfella | 1941 | Hyperion系 |
| Rock Sand | 1900 | Pot 8 o's系 |
| Rocksavage | 1915 | Pot 8 o's系 |
| Roi Dagobert | 1964 | Prince Bio系 |
| Roi Herode | 1904 | Herod系 |
| Rolls Royce | 1923 | The Tetrarch系 |
| Roman | 1937 | Teddy系 |
| Roman Ruler | 2002 | Mr. Prospector系 |
| Rosebery | 1872 | King Fergus系 |
| Rose Prince | 1919 | St. Simon系 |
| Rosicrusian | 1865 | Eclipse系 |
| Roughcast | 1978 | Hyperion系 |
| Rough'n Tumble | 1948 | Himyar系 |
| Rouleau | 1917 | Pot 8 o's系 |
| Round Table | 1954 | Princequillo系 |
| Rouvray | 1904 | St. Simon系 |
| Royal Canopy | 1914 | Herod系 |
| Royal Charger | 1942 | Nearco系 |
| Royal Gem | 1942 | Hampton系 |
| Royal Hampton | 1882 | Hampton系 |
| Royal Minstrel | 1925 | The Tetrarch系 |
| Runaway Groom | 1979 | Red God系 |
| Running Stag | 1994 | フォルティノ系 |
| Rusticaro | 1975 | フォルティノ系 |
| Ruthless | 1941 | Hyperion系 |