Hernán Leonel Buján (born 5 December 1974) is an Argentine former footballer who played as a midfielder currently first-team coach of Al-Ittihad.
In 1999, he signed for Argentine side Instituto.
He was nicknamed "spark plug" while playing for the club.
He has been close friends with Argentine football manager Marcelo Gallardo.
This biographical article related to an Argentine association football midfielder is a stub.