Vasily Sinaisky (1876–1949) – professor of  the  University of Latvia  from 1922 to 1944, where he read lectures on Civil law.   >>

Natalia Sinaysky (1914-2006) – a daughter of Professor Sinaysky. Worked as  specialisit in the fields of customs and tax law in the institutions of the European  Economic Community. >>

Alexander Sirotin (1883-?) –  a member of the People's Council of Latvia in 1919-1920, public figure, master ceramist. >>

Polina Sjakste (1929–2019) – a Docent of the Riga Medical Institute, from 1990 – Latvian Medical Academy. >>

Tatjana Sjakste (1953-2016) – Doctor of Biology (Dr. biol.), leading researcher at the Institute of Biology of the University of Latvia. >>

Nikolay Skachkov (1948) – Doctor of Emgineerig (Dr. sc. ing.), lecturer of the Riga Polytechnic Institute. >>

Konstantin Sklyarevich (1921–2003) – Habilitated Doctor of Computer Science (Dr. habil. sc. comp.), professor of the Riga Institute of Civil Aviation engineering, senior scientific collaborator of the Institute of Electronics and Computing Engineering of the Academy of Sciences of Latvia (1975-2003). >>

Adolf Skokovsky (1931-2018) – a teacher of Russian language and literature. From 1962 to 1975 – Director of Riga 48th Secondary School, since 1975 – Director of Riga 78th Secondary School (from 1989 to 1998 –  Riga 2nd Technical Lyceum, from 1998 to 2001 –  Riga city gymnasium "Anninmuizha",  from 2001 – Riga Secondary School "Anninmuizha"). >>

Nikolay Skrinnikov (1875–1955) – a colonel of the Russian and Latvian Armies, lawyer. >>

Vyacheslav Skripnik (1969–2020) – Riga photographer. >>