Antoni Kazimierz Ostrowski

{{Short description|Polish Catholic archbishop}}

{{Infobox Christian leader

| type = Archbishop

| honorific-prefix = His Excellency

| name = Antoni Kazimierz Ostrowski

| honorific-suffix =

| title = Archdiocese of Gniezno

| image = Antoni Ostrowski by Łukasz Smuglewicz.PNG

| imagesize = 200px

| alt = Antoni Kazimierz Ostrowski

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| church = Roman Catholic

| archdiocese = Gniezno

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| coat_of_arms = POL COA Grzymała.svg

| coat_of_arms_alt = Episcopal coat of arms of Archbishop Antoni Kazimierz Ostrowski,

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| birth_date = 31 March 1713

| birth_place = Ostrów

| death_date = 28 August 1784

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| nationality = Polish

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Antoni Kazimierz Ostrowski (1713–1784) was a Polish priest and politician. He was bishop of Inflanty (1753–1763), bishop of Kujawy (1763–1776) and archbishop of Gniezno (also, Primate of Poland) (1777–1784). He was one of the Polish nobles in Russian service and supported their position, including presiding over the Partition Sejm in 1773–1775.

He was son of Ludwik Ostrowski and Katarzyna.