J. Steven Hart is a prominent American lobbyist and founding partner of the bipartisan lobbying firm Williams & Jensen, established in 1987 in Washington, D.C. With more than four decades of experience in government affairs, Hart has built a reputation for representing clients in the energy sector, particularly coal interests such as Murray Energy Corporation (now part of American Consolidated Natural Resources). His work focuses on navigating legislative and regulatory challenges related to fossil fuels, environmental policies, and energy production, often advocating for policies that support the coal industry amid transitions to renewable energy sources. Hart's firm, Williams & Jensen, is known for its bipartisan approach, serving a diverse clientele including energy companies, defense contractors, and trade associations.

Before entering the lobbying world, Hart served as chief of staff to U.S. Senator Mitch McConnell (R-KY) from 1985 to 1997, where he played a pivotal role in McConnell's early Senate tenure, helping to shape strategies on appropriations, judiciary matters, and campaign finance reform. A native of Kentucky, Hart's career has been deeply intertwined with the state's coal-dependent economy and Republican politics. Earlier in his career, he worked as a legislative aide and practiced law, drawing on his legal background to bridge Capitol Hill and private sector interests.

Hart earned a Bachelor of Arts from the University of Kentucky in 1973 and a Juris Doctor from Harvard Law School in 1976. He maintains a relatively low public profile but wields significant influence through long-standing relationships in Congress and the administration. His efforts have drawn scrutiny from environmental groups critical of coal lobbying, though he has not been directly implicated in major scandals.