Alaksandr Kazulin (or Alexander Kozulin) (Belarusian: Аляксандр Уладзіслававіч Казулін, Russian: Александр Владиславович Козулин, born 25 November 1955 in Minsk), is the former leader of the Belarusian Social Democratic Party and one of the candidates who ran for the office of President of Belarus on March 19, 2006.

He was a rector of the Belarusian State University from 1996 to 2003 and a government minister serving under Belarus President Alexander Lukashenko but later fell out of favor. He holds a PhD in mathematics and pedagogy. He is married and has two daughters.

Several weeks before the election, on March 2, 2006, Kazulin was beaten and detained by police after attempting to enter the All Belarusian People's Assembly. He was charged with disorderly conduct and released after being held in custody for eight hours.

During the events following the March 19 presidential election, on March 25, Kazulin was present in a confrontation between demonstrators and police. Reportedly he walked to the commanding officer with flowers in his hand, and police knocked him off his feet, beat him up, and then detained him. In a post-election interview, despite Lukashenko's win, Kazulin said, "We're not afraid of tanks and violence; we're afraid of prisons and having no freedom. We're tired of living in a spiritual prison."