Blue Mountains Christian School commenced in 1982, and was then known as Gateway Christian School, with 17 students in one class K to 4 in a church hall in Bowenfels, near Lithgow, under Ruth Blackburn as Principal. In 1983 the school moved to Marrangaroo with classes K to 5. By 1985 the school had 60 students in classes K to 7. 1986 saw the school operate from two campuses. The Bowenfels campus had classes K to 8 and numbered 75 students. A K to 6 campus in the old convent building in Hat Hill Road, Blackheath, catered for 30 students. By 1987 the two campuses joined and operated from the Hat Hill Rd site with 111 students from K to 9, with George Glanville as Principal.
The school moved to its current site in Term 4 of 1988, with 151 students from K to 10. In 1990 Blue Mountains Christian School (then Gateway) presented its first students for the HSC.
The current site occupied by Blue Mountains Christian School was first used in 1888 as a boarding establishment. A brick building was built on the site of the bottom oval by Ms Elliott and Ms Taylor, to be used as a hotel with panoramic views over Kanimbla Valley. It never opened and was owned by the bank in 1892-1893. A Mr Lindeman ran it as a ladies boarding house for a time, when it was sold to Dr Paton who named it ‘Cramnond’.
It became Osborne Ladies College at the turn of the century with Miss Violet Gibbons as the Headmistress. The college closed in the 1950’s and the property was bought by the World Wide Church of God, who built the school’s present building. The old Osborne College burned down in the 1960’s bushfires. The administration area of Blue Mountains Christian School has been built with bricks from the College building. A group called Logos bought the site in the 1980’s and operated a school. Gateway bought the site in 1988.
In 1995 students studying for their HSC began a ‘pathways’ program, where students study three HSC subjects in Year 11, and three subjects in Year 12, thus completing their HSC over two years.
In 1999 the school changed its name to Blue Mountains Christian School and introduced a new uniform.
Over the period of 1982 to the present the school has developed as a single stream K to HSC school, providing a caring Christian educational environment for students and opportunities for parents to be partners in their children’s education.