This paper tests the “disestablishment thesis’ that America’s Protestant Establishment has declined over the course of the century, especially in the last 30 years. Using Who’s Who data from 1930, 1950, 1970, and 1992, we examine the religious affiliations of American elites, and the extent to which religious groups are over- or under-represented among elites relative to their numbers in the total U.S. population. Results support claims that the Protestant Establishment has lost prominence over the years. The data also indicate that there are more Catholics, Jews, and Lutherans among elites. However, other Protestant groups (e.g., Baptists) and Catholics remain under-represented in Who’s Who. Establishment groups and other elite religions (Unitarian-Universalists and Quakers) remain over-represented. Jews have gained relative to their numbers in the total population and are over-represented. We use a neo-Weberian framework to interpret the findings.