Kazimieras Venclauskis (27 February 1880 – 24 February 1940) was a Lithuanian attorney, politician, and philanthropist. After graduating from the University of Tartu and completing the mandatory five-year practice at a court and prosecutor's office, he moved to Šiauliai where he established a successful private law practice in 1908 and lived until his death. Venclauskis joined the Social Democratic Party of Lithuania in 1902 and was active during the Russian Revolution of 1905. He was elected to the Šiauliai City Duma in 1911 and planned to run in the election to the Russian State Duma in 1912, but an arrest by police spoiled the plans. He was an active member or chairman of various Lithuanian societies, including Žvaigždė and Jėga that organized Lithuanian schools and Varpas that organize