Bernard Lonergan S.J. (1904-84) is unusual among major theologians in engaging deeply with economic theory. In the 1940s he developed his own dynamic multisectoral macroeconomic model, informed by reading of Smith, Marx, Keynes, Hayek, Schumpeter, and later Kalecki. Lonergan’s economic research is little known because the economic manuscripts were not published in his lifetime, and his interactions with professional economists were limited. In the 1970s, however, when he returned to economics he engaged with Post-Keynesians and taught a graduate course on macroeconomics at Boston College until illness overtook him. This paper places Lonergan’s economic research in the context of his overall intellectual project, outlines his macroeconomic model and associated theory of the business cycle, then evaluates his contribution in relation to mid-twentieth century macroeconomics and considers whether it has anything to offer contemporary economists. Whatever view we take of his theoretical contributions, Lonergan’s work opens up connections between economics and theology.