Sergei Fyodorovich Aleinik[a] (born 28 January 1965) is a Belarusian politician who served as Minister of Foreign Affairs of Belarus in 2022–2024.

He studied German and English at the Minsk State Pedagogic Institute of Foreign Languages and the Diplomatic Academy in Vienna.

In the early 1990s, Aleinik enrolled for a post-graduate study in International Relations at The Diplomatic Academy of the Ministry of Foreign Affairs of Austria.

While in the Netherlands, he was promoted to the rank of ambassador and deployed to the United Nations Office in Geneva with accreditation to the Holy See and the Sovereign Order of Malta.

[2] During his term in office, he established diplomatic relations with Nigeria, Ethiopia, Indonesia and Brazil.