During his teaching years, Paul Christianson published Reformers and Babylon: English Protestant Apocalyptic Visions from the Reformation to the Eve of the Civil War (University of Toronto Press: Toronto, Buffalo, London, 1978), Discourse on History, Law, and Governance in the Public Career of John Selden, 1610-1635 (University of Toronto Press: Toronto, Buffalo, London, 1996) and a number of articles on 16th and 17th Century British History. His book on Selden was awarded the John Ben Snow Foundation Prize by the North American Conference on British Studies as the best book by a North American scholar in any field of British studies dealing with the period from the Middle Ages through the eighteenth century published in 1996. He also received the Frank Knox Award for Excellence in Teaching in 1993 and the Queens University Alumni Association Award for Excellence in Teaching in 1997.
Since retirement, his research has focused on the architectural history of 19th century Anglican Churches built in the greater Kingston area. This has resulted in the publication of six articles in the Journal of the Society for the Study of Architecture in Canada/Journal pour l矇tude de larchitecture au Canada : St. Marks Anglican Church, Barriefield, and the Gothic Revival in Canada West, vol. 35, no. 1, (2010,), pp. 17-30, St. Johns Anglican Church, Portsmouth, and the Gothic Revival in Canada West, vol. 38, no. 1 (2013), pp. 5-20, and Edward John Baker Pense and the Additions made to St. James Anglican Church, Kingston, and St. Marks Anglican Church, Barriefield, 1886-1897, vol. 39, no. 2 (2014), CORRECT STYLE Recommendations on Church Architecture, Furnishings, and Worship in the Anglican Diocese of Toronto 1849-1850, vol. 42, no. 1, (2017), pp, 79-108, The Second St. Georges Anglican Church, Kingston, Upper Canada, 1822-1828, vol. 45, no. 1, (2020), pp. 42-62, Changes to the Architecture of St. Georges Anglican Church, Kingston, 1837-1847, vol. 47, no. 1, (2022), pp. 58-101. In addition, he has published papers in A Collection of Talks of Historical Interest 2008, 2010, 2012, published annually by the Pittsburgh Township Historical Society: Theology and the Architecture of Anglican Churches in Kingston from 1825-1867, (Kingston, 2009), pp. 33-44, The Design, Building, and Rebuilding of St. Pauls Anglican Church, Kingston, 1844-1856, (Kingston, 2011), pp. 7-23, and The Building of St. James Anglican Church, Stuartville: Social and Architectural Sources, 1844-1845, (Kingston, 2013), pp. 11-25, and Who made the Early Drawings of St. Georges and the Kingston City Hall?, Historic Kingston, vol. 70, (2020), pp. 30-41 .