Sigitas Tamkevičius (born 7 November 1938) is a Lithuanian prelate and Cardinal of the Roman Catholic Church and Archbishop emeritus of Kaunas.

He spent several years in the military service in the Soviet Army and then continued his theology studies, graduating from the seminary in 1962.

Tamkevičius was among the initiators of the petition action protesting the Soviet discriminating restrictions on the Kaunas Seminary.

While vicar in Simnas parish, Tamkevičius initiated the underground publication of the Chronicle of the Catholic Church of Lithuania in 1972.

The Chronicle registered and made public in the West the facts of religious discrimination in Soviet Lithuania.