Mehdi bey Hajinski Suleyman bey oglu (Azerbaijani: Mehdi bəy Hacinski Süleyman bəy oğlu; 1879–1941) was an Azerbaijani actor, publicist and statesman who served as the State Controller of Azerbaijan Democratic Republic and first general secretary of Parliament of Azerbaijan, and was a member of Azerbaijani National Council.

Considered a noble writer, Hajinski published numerous articles about the Azerbaijani theater, arts and culture of the country, Since 1908, he also acted on stage.

[1] He was the person who first awarded Uzeyir Hajibeyov for his Leyli and Majnun opera.

[2] Upon the dissolution of Transcaucasian Democratic Federative Republic, Hajinski became a member of the Presidium of Azerbaijani National Council, an interim body of the government which proclaimed the independence of Azerbaijan Democratic Republic on May 28, 1918.

[4][5] When the third cabinet of Azerbaijan Democratic Republic was formed by Fatali Khan Khoyski, Hajinski was appointed State Controller of ADR.