Biblical typology served as a crucial interpretive tool for the biblical exegesis of Jonathan Edwards (1703–1758). Presently, there is significant inquiry into the biblical exegesis and exegetical methods of Edwards, yet there has been relatively little attention paid among scholarship to how fountain as a type featured in his theology, especially concerning the Trinity. He utilized the type of fountain, exegeted from biblical texts and drawn from Puritan sources, to describe his doctrine of the Trinity, such as the “fountain of all,” “fountain of life,” and “fountain of happiness.” Through an analysis of his unpublished sermonic material, notebooks, and “Miscellanies” entries, this paper examines how Edwards utilized the language of fountain to elucidate trinitarian relations, tracing his reliance on Puritan and latitudinarian divines. Thus, within demonstrative examples from Thomas Case (1598–1682), Stephen Charnock (1628–1680), Thomas Goodwin (1600–1680), and Ralph Cudworth (1617–1688) will be explored to situate how Edwards developed a typology of fountain. By examining specific entries like “Misc.” no. 94, where Edwards discussed the Spirit as the source of spiritual comfort and delight, this paper underscores the theological depth and significance of fountain as a type and his tendency to use the idiom of Scripture to substantiate his doctrinal claims.