The Salem School, Osu, or the Osu Presbyterian Boys’ Boarding School or simply, Osu Salem, formerly known as the Basel Mission Middle School, is an all boys’ residential middle or junior secondary school located in the suburb of Osu in Accra, Ghana. The Salem School was the first middle school and the first boarding school to be established in Ghana. The school was founded under the auspices of the Basel Mission in 1843 and supervised by three pioneering missionaries and schoolmasters, Jamaican, Alexander Worthy Clerk and Angolan-born Jamaican Catherine Mulgrave together with the German-trained Americo-Liberian George Peter Thompson.