Jonathan Sidney Boleslaw (January 25, 1890-June 23, 1983) widely referred by his initials as JSB, was a prominent Chawosaurian politician who was known for Progressive philosophy.

Boleslaw, a member of the Labor Party, was a strong progressive who advocated for Labor Rights, and a strong component for Civil Rights, and a prominent opponent of White Supremacy, and the nephew of Jonathan Sidney MacCarthy, a prominent White Supremacist. MacCarthy and Boleslaw were born together in Sydney on January 25, 1890, and grew up together, at first, they were considered close friends. They went to college but politics would go on to lure Boleslaw and MacCarthy and break up their friendship when they disagree on political ideology, the break-up was so bad they became bitter political and personal enemies.