The Rev William Rattray was the owner and occupier of 21 (then 33) Queen Square between 1905 and 1925. The previous occupier had been the builder of the terrace, Alexander Thomson.
Rattray was the minister at Abbotsford Chalmers Parish Church at 100 Pollokshaws Road . The church and adjacent Abbotsford School survive, the former converted to supported residential use for young adults, as Quarriers James Shields Service, the latter as Al Khalil College.
Abbotsford Chalmers Church, Glasgow, originated with the congregation of Maitland Free Church, who built a church in Rose Street, Gorbals, in 1862 but later moved to Devon Street and petitioned for admission to the Church of Scotland. They were admitted and became Abbotsford Parish Church quoad sacra in 1877, terminating in 1933 on uniting with Chalmers South as Abbotsford Chalmers Church. The latter congregation worshipped in the former Chalmers South building in Pollokshaws Road at Cavendish Street, until terminated in turn in 1973 on uniting with three other congregations as Gorbals. As a Church of Scotland charge it was in the presbytery of Glasgow and the synod of Glasgow and Ayr (later Clydesdale) .
By co-incidence, or perhaps not, Alexander Thomson the brickmaker, contractor and builder of Queen Square, was based almost next door at 138 Pollokshaws Road, directly under the the adjacent M74 flyover.