Rieckhoff graduated from Amherst College in 1998 with a BA in Political Science. Following his service as an Army specialist, he graduated from Officer Candidate School in 2001 and was commissioned as an officer. In February 2002, Rieckhoff began the Infantry Officers Basic Course at Fort Benning, Georgia and graduated in June 2002.

Rieckhoff enlisted in the U.S. Army Reserves on September 15, 1998 and completed Basic Combat Training and Advanced Individual Training at Fort McClellan, Alabama. He then served in the U.S. Army Reserves, as a Specialist with the 812th Military Police Company. While working on Wall Street at J.P. Morgan in 1999, Rieckhoff transferred to the New York Army National Guard. He graduated from Officer Candidate School in June 2001 and was named a Distinguished Military Graduate. Rieckhoff selected infantry as his branch and joined A Company, 1/105th INF (Light).

Rieckhoff left Wall Street on September 7, 2001 with plans to travel and complete additional military schooling. On the morning of September 11, Rieckhoff was at his apartment on 24th Street in Manhattan when the first plane hit the World Trade Center. His unit was formally activated for rescue and security operations later that evening.

In January 2003, Rieckhoff was called to deploy to Iraq. Two days later, he was on a plane to join the 3rd Infantry Division at Fort Stewart, Georgia. Rieckhoff was then assigned as a Platoon Leader for 3rd Platoon, B Company, 3/124th INF (Air Assault) FLNG. The unit was attached to 1st Brigade, 3rd Infantry Division and spent almost a year conducting combat operations in Baghdad, Iraq. Third Platoon conducted over 1,000 dismounted and mounted combat patrols. All thirty-eight of the men in Rieckhoff's platoon returned home alive.

Rieckhoff wrote a book describing his experiences in Iraq and activism afterwards entitled Chasing Ghosts (2006).

Paul Rieckhoff, in his position as the founder of IAVA, has appeared on many television and radio programs including NBC Nightly News, World News With Charles Gibson, The Early Show, Tavis Smiley, The Charlie Rose Show, The NewsHour with Jim Lehrer, Anderson Cooper 360°, The Rachel Maddow Show, Real Time with Bill Maher, and The Henry Rollins Show.

He has written articles and opinion columns for The New York Times, Associated Press, Wall Street Journal, USA Today, Los Angeles Times, Washington Post, Newsweek, The Huffington Post, and Military.com.

Rieckhoff was recently inducted into the Global Ashoka Fellowship in recognition of his innovation and entrepreneurship on behalf of new veterans.

Named one of GQ’s “ 50 Most Powerful People in D.C.” in 2009, Rieckhoff has been honored with the Common Ground “Celebrating Home Award” and the Generation Engage “Lewis Cullman Civic Engagement Award” for his leadership in the service community. In 2004, he was also honored by Esquire magazine as one of “America’s Best and Brightest.” Rieckhoff is also a member of the Council on Foreign Relations.