Saint John of Kronstadt (Иоанн Кронштадтский) (October 19, 1829, Sura, Arkhangelsk–December 20, 1908, Kronstadt) was a Russian Orthodox archpriest and member of the synod of the Russian Orthodox Church.
He was born as Ivan Ilyich Sergiyev (Иван Ильич Сергиев) in 1829. From 1855, he worked as a priest in Saint Andrew's cathedral in Kronstadt. Here, he greatly committed himself to charity, especially for those who were remote from the church, and travelled extensively throughout the Russian empire. He was a member of the right extremist Sojuz Russkogo Naroda (Alliance of the Russian people), but did not commit himself politically. He was already greatly venerated at the time he died.
He was canonized by the Russian Orthodox Church Outside of Russia in 1964 and by the Russian Orthodox Church in 1990. The second largest monastery of St Petersburg (by community size) is dedicated to St John of Kronstadt.