Saint Mark's College is a bilingual high school in Monte Grande, part of Greater Buenos Aires, Argentina.
Its staff provides instruction in both English and Spanish and the school offers education at the kindergarten, elementary and secondary levels. It offers the International Baccalaureate program.
The school was founded in 1958 by two sisters Poupeé and Emilia Marteletti, and by Susana Raquel Raffo. Its motto is "Dominus Regit Me" which translates to "The Lord is my Guide".
The high school features three houses which are named in honour of Wilkie Collins, Sir Walter Scott and John Milton.