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

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

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). >>

Ludmila Sproge (1953) – professor, from 2002 Head of the Department of Russian and Slav languages of the faculty of Humanitarian Sciences of the University of Latvia. >>