The school was founded by the Anglican Church as a ladies' school. It later merged with Mrs. Vfyhuis's school, also founded in 1870, and then with the DeSaffon school. Mrs. Vfyhuis was offered headship of the combined schools in 1875. The school's first home was at Brickdam and Manget Place, and then at "Minto House" on Waterloo Street. It later moved to "Lamaha House" at Carmichael and Lamaha Streets, the property of Bishop E.A. Parry.

In 1907 Bishop E.A. Parry moved the school to "Woodside House" (now known as "Transport House") on Main Street, and it became known as "Woodside House School". In 1921 the school moved to its present location at Carmichael and Murray (now known as Quamina) Streets.

• In 1922 Bishop E.A. Parry retired and the school then became known as "The Bishops' High School". Bishop Parry died in 1936 and the "Oswald Parry Hall" was opened at the School.
• In January 1936, the School was handed over to the Government of British Guiana. The new building was opened on January 5, 1946.
  
• In 1970 the School celebrated its centennial.
  
• The Bishops' High School became a co-educational institution in 1975. This was accomplished by transferring approximately one hundred and fifty boys into the 2nd, 3rd, Upper 5th and Lower 6th forms from the Queens College High School (QC), which was a unisex institution. Boys were also admitted into the first form.
  &Co-ed Boys' List
• In 1995 Bishops' High School celebrated its 125.