Gabriel Lenkiewicz (15 March 1722, Polatsk – 21 November 1798, Polatsk) was a Belarusian Jesuit priest, and Temporary Vicar General of the Society of Jesus from 1785 until 1798, at a time when, being suppressed in all Catholic countries, the Society of Jesus was still surviving in Russia.
Lenkiewicz was born and died in Polatsk, Polish–Lithuanian Commonwealth (today's Belarus), of aristocratic Polish–Lithuanian family. He joined the Jesuits after completing the 'Humanities'. He did his philosophy (1748–51) in Belarus, and then studied mathematics, astronomy and architecture in the Academy of Vilnius (1752–54). This was followed by theology in Warsaw (1754–58) during which he was ordained priest (1757). After a few years of teaching mathematics in Warsaw he was sent to Rome (Roman College) for further specialization in Architecture (1762–65).
Back in Poland he was appointed to teach science at Polatsk (1765–68) but he made himself a name rather as architect of public and ecclesiastical building, including the construction of new premises for the Jesuit College of Polatsk (of which Stanislaus Czerniewicz was the Rector). After the Suppression of the Society of Jesus (1773) he became the right-hand man of the Vicar Czerniewicz, negotiating with him the survival of the Jesuits with Empress Catherina the II of Russia, all the while making sure that the standard of scientific education in Polatsk remained high. To Lenkiewicz, 'quality education' was an absolute necessity if the Society was to survive in Russia.