Alexander Knox (17 March 1757 – 17 January 1831) was an Irish theological writer.
As a boy and young man, Alexander Knox befriended and corresponded with John Wesley, and - though he later asserted his theological independence from Methodism - he later published defences of Wesley against John Walker and Robert Southey.
In the 1790s Knox entered political life, briefly (in 1798) becoming private secretary to Lord Castlereagh and publishing Essays on the political circumstances of Ireland (1799) before retiring from politics in 1799.
Knox lived in or near Dublin for the final three decades of his life, becoming known as the 'sage of Bellevue'. Together with his friend John Jebb, bishop of Limerick, Knox developed a distinctive style of high-churchmanship (evidenced in his theology of sacraments) which also respected strains in evangelicalism, Methodism and seventeenth-century latitudinarianism. Knox wrote in defence of Catholic emancipation.