Konstantinos Mousouros (Greek: Κωνσταντίνος Μουσούρος, Turkish: Kostaki Musurus Paşa; 1807–1891), also known as Kostaki Musurus Pasha, was an Ottoman Greek diplomatic official of the Ottoman Empire who served as ambassador to Greece, Austria, Great Britain, Belgium, and the Netherlands.

Mousouros became the first ambassador of the Ottoman Empire to the newly independent Kingdom of Greece in 1840, a position he kept until 1848.

In 1847–48 he was a central figure in the events known as Mousourika (Μουσουρικά), which led to his temporary recall and the breakdown of relations between the two states.

In 1850 he took up the post of Ottoman ambassador to the Great Britain and Ireland, which he kept for 35 consecutive years, until his retirement in 1885.

He was married and had a son, Stephanos Mousouros, who later became Prince of Samos and Ambassador to the United Kingdom.