| Name | Sex | Colour | Registration | Foaling Date | Reg Status | Competition Status |
|---|---|---|---|---|---|---|
| SOMERVILLES ROSY | Mare | CHESTNUT | 32542 | Stud Book | Not Eligible | |
| SOMETHING AMBER | Mare | CHESTNUT | 73723 | 02/08/1976 | Stud Book | Not Eligible |
| SOMETHING BRIGHT | Mare | BAY | 39524 | 08/09/1970 | Stud Book | Deceased |
| SOMETHING CRYSTAL | Mare | CHESTNUT | 24552 | Stud Book | Not Eligible | |
| SOMETHING MAGIC | Gelding | BLACK | 101343 | 01/11/1985 | Stud Book | Not Eligible |
| SOMETHING SPECIAL | Gelding | CHESTNUT | 72120 | 20/12/1980 | Stud Book | Not Eligible |
| SOMETHINGROYAL - HSH | Mare | BROWN/BLACK | 263809 | 27/10/2018 | Stud Book | Eligible |
| SOMETIME LADY | Mare | BROWN | 34095 | 10/08/1974 | Stud Book | Not Eligible |
| SON FLAVOR | Mare | CHESTNUT | 63584 | 14/12/1975 | Stud Book | Not Eligible |
| SON MASTER | Stallion | CHESTNUT | F3867 | 10/09/1975 | Foal Recorded | Not Eligible |
| SON OF A GUN | Gelding | CHESTNUT | 28582 | Stud Book | Deceased | |
| SON OF COPPER - HSH | Gelding | GREY | 35536 | 04/10/1974 | Stud Book | Deceased |
| SON OF DALLAS | Stallion | BLACK | F30968 | 03/12/1981 | Foal Recorded | Deceased |
| SON OF DAYBREAK | Stallion | CHESTNUT | 12605 | Stud Book | Deceased | |
| SON OF EPISTLE | Stallion | CHESTNUT | 27777 | 13/10/1971 | Stud Book | Deceased |
| SON OF MATTEWAI | Stallion | GREY | 1860 | 30/09/1964 | Stud Book | Deceased |
| SON OF SEER | Stallion | PALOMINO | C1-166748 | 15/12/2001 | First Cross | Not Eligible |
| SON OF SKITEY | Stallion | BROWN | F17221 | 06/10/1978 | Foal Recorded | Not Eligible |
| SON OF STEVE | Gelding | CHESTNUT | 34079 | 12/09/1974 | Stud Book | Deceased |
| SON OF THE TUDORS | Stallion | GREY | 25535 | 20/11/1965 | Stud Book | Deceased |
| SON OF TINKER | Stallion | CHESTNUT | F29834 | 16/10/1981 | Foal Recorded | Deceased |
| SON OF YOUNG GUN | Gelding | BAY | C1-196058 | 28/10/2007 | First Cross | Not Eligible |
| SONAKATO GREY | Mare | GREY | 77480 | 15/12/1986 | Stud Book | Not Eligible |
| SONAR - HSH | Gelding | BAY | 231448 | 14/10/2012 | Stud Book | Eligible |
| SONAR QUEEN | Mare | BAY | 4697 | 01/01/1968 | Stud Book | Deceased |
| SONATA | Mare | BAY | 55130 | 17/12/1976 | Stud Book | Not Eligible |
| SONATAS COMET - HSH | Stallion | BROWN | 198129 | 08/09/2011 | Stud Book | Not Eligible |
| SONBRI BRONZE - HSH | Stallion | CHESTNUT | 168324 | 06/09/2004 | Stud Book | Not Eligible |
| SONDA | Mare | CHESTNUT | 3031 | 01/01/1967 | Stud Book | Deceased |
| SONDARLYN | Stallion | BROWN/BLACK | F10008 | 10/11/1977 | Foal Recorded | Not Eligible |
| SONETTA | Mare | BROWN | 66372 | 12/11/1972 | Stud Book | Deceased |
| SONETTE | Mare | CHESTNUT | 19834 | Stud Book | Deceased | |
| SONG - HSH | Mare | BLACK | 263988 | 11/12/1989 | Stud Book | Deceased |
| SONG AND DANCE MAN | Gelding | BROWN | 68001 | 24/08/1979 | Stud Book | Not Eligible |
| SONG N DANCE | Gelding | BROWN | C1-236387 | 02/11/2014 | First Cross | Not Eligible |
| SONGSTER | Gelding | BAY | 43212 | 06/04/1986 | Stud Book | Deceased |
| SONIA LEE | Mare | GREY | 17281 | 01/11/1970 | Stud Book | Deceased |
| SONIA STAR | Mare | BAY | 12448 | Stud Book | Deceased | |
| SONIC SPARK | Stallion | BAY | R-267730 | 27/10/2022 | Base Registry | Eligible |
| SONIE | Mare | PALOMINO | 31447 | 01/09/1974 | Stud Book | Not Eligible |
| SONITAFEX REVIEW | Gelding | CHESTNUT | C2-238877 | 25/09/2011 | Second Cross | Eligible |
| SONITAS WARCRY | Gelding | BUCKSKIN | C1-190106 | 22/12/2005 | First Cross | Not Eligible |
| SONJA | Mare | BROWN | F17696 | 03/02/1979 | Foal Recorded | Not Eligible |
| SONJAS BUDDY | Mare | BAY | 75946 | 28/02/1975 | Stud Book | Not Eligible |
| SONNEMARG | Mare | CHESTNUT | 76379 | 28/10/1983 | Stud Book | Deceased |
| SONNET | Mare | BAY | 13868 | 01/01/1966 | Stud Book | Deceased |
| SONNETTES JOY | Mare | CHESTNUT | 101268 | 21/11/1987 | Stud Book | Not Eligible |
| SONNY | Gelding | CHESTNUT | 10393 | Stud Book | Deceased | |
| SONNY BOY | Gelding | CHESTNUT | 11743 | Stud Book | Deceased | |
| SONNY HONEY | Gelding | BAY | F40365 | 06/09/1985 | Foal Recorded | Not Eligible |
| SONNY JIM | Gelding | BROWN | 53580 | 06/11/1975 | Stud Book | Not Eligible |
| SONNY KATE | Mare | BAY | 66985 | 01/08/1981 | Stud Book | Not Eligible |
| SONNY LAD | Gelding | BAY | 22402 | Stud Book | Deceased | |
| SONNY QUEEN | Mare | BAY | 80546 | 07/12/1992 | Stud Book | Not Eligible |
| SONNY SILVER JUBILEE - HSH | Stallion | CHESTNUT | SM-157684 | 12/12/1999 | Special Merit - Stud Book | Not Eligible |
| SONNY STAR BID | Gelding | BAY | 73685 | 19/09/1980 | Stud Book | Deceased |
| SONNY VALE | Stallion | CHESTNUT | F4868 | 10/10/1976 | Foal Recorded | Not Eligible |
| SONNYBROOK RAMBLER | Stallion | CHESTNUT | 258338 | 20/12/2017 | Stud Book | Not Eligible |
| SONNYS GAL | Mare | BLACK | 139128 | 01/11/1999 | Stud Book | Not Eligible |
| SONNYS GIFT | Mare | CHESTNUT | 80813 | 20/09/1990 | Stud Book | Not Eligible |
| SONOHONEY | Gelding | CHESTNUT | 55403 | 25/11/1976 | Stud Book | Not Eligible |
| SONOMA BACK IN BLACK | Mare | BLACK | C1-247305 | 28/08/2013 | First Cross | Not Eligible |
| SONOMA FOXETTE | Mare | BLACK | 256503 | 22/08/2019 | Stud Book | Not Eligible |
| SONOMA ROSE | Mare | GREY | 61499 | 01/01/1976 | Stud Book | Not Eligible |
| SONORA JOSIE - HSH | Mare | BAY | 35276 | Stud Book | Not Eligible | |
| SONPARAE | Gelding | GREY | 72778 | 01/09/1979 | Stud Book | Not Eligible |
| SONREAP DARK LADY | Mare | BLACK | 34786 | Stud Book | Not Eligible | |
| SONREAP JADE | Mare | BAY | 68140 | 29/08/1979 | Stud Book | Not Eligible |
| SONREAP TABAC | Gelding | GREY | 68130 | 16/10/1980 | Stud Book | Not Eligible |
| SONREAP TINKABELLE | Mare | CHESTNUT | 34788 | 01/08/1973 | Stud Book | Not Eligible |
| SONREAP UNCLE SAM | Gelding | CHESTNUT | 34787 | 01/08/1969 | Stud Book | Deceased |
| SONSY GOLD | Mare | CHESTNUT | 64714 | 24/08/1978 | Stud Book | Not Eligible |
| SONTAINE | Mare | BAY | 72429 | 12/01/1979 | Stud Book | Not Eligible |
| SONTANZA BABY DOLL | Mare | CHESTNUT | 61481 | 18/11/1978 | Stud Book | Not Eligible |
| SONTANZA FELICITY | Mare | PALOMINO | 61482 | 15/08/1978 | Stud Book | Not Eligible |
| SONTERS FLIRT | Mare | GREY | 26626 | 03/10/1969 | Stud Book | Deceased |
| SONVERISSA MISCHIEF MOORE | Mare | BROWN | 32383 | 01/01/1968 | Stud Book | Deceased |
| SONYA | Mare | CHESTNUT | 8322 | 01/08/1969 | Stud Book | Deceased |
| SOOKIE | Mare | CHESTNUT | 43149 | 30/09/1968 | Stud Book | Deceased |
| SOOLAIMON | Gelding | BAY | 12269 | 05/11/1968 | Stud Book | Deceased |
| SOOTHSAY | Gelding | BAY | 20421 | Stud Book | Deceased | |
| SOOTY | Mare | BROWN | 4715 | Stud Book | Deceased | |
| SOPHIE | Mare | CHESTNUT | 10084 | Stud Book | Deceased | |
| SOPHIE STYLISH | Mare | BAY | R-255831 | 12/08/2019 | Base Registry | Eligible |
| SOPHIES CHOICE - HSH | Mare | CHESTNUT | 166102 | 11/10/2003 | Stud Book | Not Eligible |
| SOPHISTICATED REBEL | Gelding | CHESTNUT | C1-265664 | 10/11/2017 | First Cross | Eligible |
| SOPHISTICATED SPINACRE | Mare | PALOMINO | C1-265242 | 02/09/2021 | First Cross | Eligible |
| SOPHISTICATION | Mare | CHESTNUT | C1-234591 | 05/10/2011 | First Cross | Not Eligible |
| SOQULU MOONSHINE | Mare | BAY/GREY | 48880 | 01/08/1977 | Stud Book | Deceased |
| SORAYA | Mare | PALOMINO | 18746 | 10/10/1967 | Stud Book | Deceased |
| SORCERER | Gelding | BAY | 123167 | 03/08/1992 | Stud Book | Not Eligible |
| SOREL BONJOVI | Gelding | CHESTNUT | C1-190318 | 20/10/2005 | First Cross | Deceased |
| SORELLA | Mare | CHESTNUT | 38770 | Stud Book | Not Eligible | |
| SORELLAS SILAS - HSH | Gelding | BAY | 251793 | 23/09/2015 | Stud Book | Eligible |
| SORELLAS SOFIA - HSH | Mare | GREY | 249191 | 22/09/2016 | Stud Book | Eligible |
| SORELLE HILL | Stallion | CHESTNUT | F6496 | 21/08/1976 | Foal Recorded | Not Eligible |
| SORENTO | Mare | CHESTNUT | 29605 | Stud Book | Not Eligible | |
| SORESSIMA | Mare | GREY | 74126 | 02/07/1974 | Stud Book | Not Eligible |
| SORITA | Mare | BAY | 48743 | 23/02/1977 | Stud Book | Not Eligible |
| SOROCCO | Mare | CHESTNUT | 43763 | 23/07/1975 | Stud Book | Not Eligible |