Mentone Grammar (formerly known as simply The Boys' Grammar in the local community) is an independent, Anglican co-educational grammar day school in Mentone, a suburb of Melbourne, Victoria, Australia.

Mentone Grammar School was founded on 3 March 1923 by a group of Anglicans who had a high profile in the town, supported by the local Mentone Anglican vicar.^[4] Mentone Grammar remained a boys only school until 2006 when the school decided to accept female students. Prior to this, the school hierarchy announced, in July 2005, its co-educational intent after a merger proposal put forth by the Board of Management was rejected by nearby Mentone Girls' Grammar School, its sister school.^{[citation needed]}

The school is renowned for its 'Together-Apart-Together' learning model, where classes are co-educational from ELC – Year 4 and from Years 10 – 12, with students learning in single-gender classes through Years 5 – 9.^[5]

As of 2024, annual fees for a Year 12 student studying at Mentone Grammar were slightly over $30,000.^[6]

The Mentone Grammar Army Cadet Unit (MGACU) is an Australian Army Cadets school-based unit, founded and operating continuously since 1943. It is part of the 31st Battalion (Melbourne Schools) and now represents the largest school-based Unit in Victoria.

Leadership is highly valued in the Unit and being part of the MGACU provides opportunities for Senior students to develop leadership skills, together with expertise in the areas of fieldcraft, first aid and navigation. All Year 9 students join the Cadets for one year then have the option to continue on in Years 10, 11 and 12 to further develop their skills, training and leadership of incoming recruits.

Former AFL player and coach, Brenton Sanderson commenced as the school's Director of Sport in 2023. Their sequential sports program provides opportunities for students of all abilities to benefit from elite coaching programs, established through partnerships with highly credentialled coaches, talent pathway programs and professional sporting clubs.

Saturday sport is compulsory for all students in Years 7–12, with boys competing in the Associated Grammar Schools of Victoria (AGSV) competition and girls in the combined AGSV / Associated Public Schools (APS) competition in both Summer and Winter sports.

On Saturday 29 January 2022, Mentone Grammar's 2022 Head Prefect, Evie Stansby made Mentone Grammar sporting history by becoming the first female to earn a place on their First XI cricket team.^[7]

• Victorian Certificate of Education
• Australian Army Cadets