Holmes was a senior fellow at the Institute for Foreign Policy Analysis, a research institute associated with the Fletcher School of Law and Diplomacy, and was a research fellow at the Institute for European History in Mainz, Germany.^[when?] Holmes first joined the Heritage Foundation in 1985.^[4] While at Heritage, he was promoted to senior policy analyst for national security affairs specializing in arms control, NATO, and East-West strategic relations. He was subsequently promoted to director — and in 1992, vice president — of foreign and defense policy studies. He served in that position until 2001, and again from 2005 to 2012.

In 1995, Holmes and the Heritage Foundation authored a report advocating for an increase in funds towards ensuring the nation's defense against ballistic missiles, stating that "the threat of ballistic missile attack is clear, present, and growing."^[5]

Holmes served as founding editor of the Heritage Foundation/Wall Street Journal's annual Index of Economic Freedom, serving as co-editor from 1995 through 2002 and from 2006 through 2014.^[6] In September 2000, he testified before Congress on national missile defense. In 2002, Holmes served as Assistant Secretary of State for International Organization Affairs under Secretary of State Colin Powell, a position he held until 2005.^[7] Later in 2005, he testified before Congress about human rights issues in Cuba,^[8] and U.N. peacekeeping abuses in the Democratic Republic of the Congo.^[7]

Holmes later served on presidential candidate Mitt Romney’s Foreign Policy and National Security Advisory Team in 2012.^[9] Also in 2012, Holmes became a Distinguished Fellow at The Heritage Foundation.

Holmes has been a member of the board of directors and executive committee for the Center for International Private Enterprise, associated with the U.S. Chamber of Commerce, since 2016, and a board member since 1997.^[10]

On August 1, 2019 Holmes was confirmed by the Senate to be a member of the National Council on the Humanities.^[11]

• Holmes, Kim R; Kosminsky, Jay P; Aron, Leon Rabinovich (1990). Reshaping Europe: strategies for a post-cold war Europe. Heritage Foundation. ISBN 089195225X. OCLC 22958788.
• Holmes, Kim R; Spring, Baker (1990). SDI at the turning point readying strategic defenses for the 1990s and beyond. Heritage Foundation. OCLC 495545984.
• Holmes, Kim R (1991). The NSDAP and the crisis of agrarian conservatism in lower Bavaria: national socialism and the peasants' road to modernity. Garland Pub. ISBN 0815304145. OCLC 23462636.
• Ferrara, Peter; Heritage Foundation (Washington, D.C.) (1994). Issues: the candidate's briefing book. OCLC 44266938.
• Holmes, Kim R; Heritage Foundation (Washington, D.C.) (1994). A safe and prosperous America: a U.S. foreign and defense policy blueprint. Heritage Foundation. ISBN 0891952306. OCLC 31015926.
• Heritage Foundation (Washington, D.C.) (1995). Defending America: a near- and long-term plan to deploy missile defenses : report of the Missile Defense Study Team. Heritage Foundation. ISBN 0891952349. OCLC 32916976.
• Holmes, Kim R; Moore, Thomas Gale; Heritage Foundation (Washington, D.C.) (1996). Restoring American leadership: a U.S. foreign and defense policy blueprint. Heritage Foundation. OCLC 606036617.
• Holmes, Kim R; Przystup, James J (1997). Between diplomacy and deterrence: strategies for U.S. relations with China. Heritage Foundation. ISBN 089195242X.
• Butler, Stuart M; Holmes, Kim R (1997). Mandate for leadership IV: turning ideas into actions. The Heritage Foundation. ISBN 0891950648.
• The Heritage Foundation (2001). Index of Economic Freedom. Wall Street Journal. OCLC 816170371.
• Butler, Stuart M; Holmes, Kim R; Heritage Foundation (Washington, D.C.) (2001). Priorities for the President. Heritage Foundation. ISBN 0891950966. OCLC 45954663.
• Heritage Foundation (Washington, D.C.) (2006). Reclaiming the language of freedom at the United Nations: a guide for U.S. policymakers. The Heritage Foundation. OCLC 214285344.
• Holmes, Kim R (2008). Liberty's best hope: American leadership for the 21st century. The Heritage Foundation. ISBN 9780891952787.
• Schaefer, Brett D; Bolton, John R (2009). ConUNdrum the limits of the United Nations and the search for alternatives. Rowman & Littlefield Pub. ; Published in cooperation with the Heritage Foundation. ISBN 9781442200067. OCLC 690327206.
• Holmes, Kim R (2013). Rebound: getting America back to great. Rowman et Littlefield. ISBN 9781442223806. OCLC 915460079.
• Holmes, Kim (2015). "Ronald Reagan's Approach to the United Nations". In Kengor, Paul; Chidester, Jeffrey L (eds.). Reagan's legacy in a world transformed. Harvard University Press. ISBN 9780674967694. OCLC 890814486.
• Holmes, Kim R (2017). The closing of the liberal mind: how groupthink and intolerance define the left. New York City, NY: Encounter Books. ISBN 978-1594039553. OCLC 973807452.

• Official biography and list of publications
• Official biography, U.S. Department of State
• Articles, The Washington Times
• Appearances on C-SPAN