John E. "Jack" Potter (born 1956) is the president and CEO of the Metropolitan Washington Airports Authority since July 18, 2011. He is the former United States Postmaster General and CEO of the United States Postal Service (USPS), having become the 72nd postmaster general on June 1, 2001. Potter is the second longest-serving postmaster general, following Gideon Granger.

Potter's father, Richard, was a Manhattan letter carrier who later became a senior executive of the postal service. After graduating from Cardinal Spellman High School in the Bronx a year behind Supreme Court Justice Sonia Sotomayor, Potter attended Fordham University. He joined the postal service in 1978 as a distribution clerk in Westchester keying ZIP codes into sorting machines. After eight years in New York, including a three-year analyst's stint at 50th Street and Broadway, Potter rose rapidly through the hierarchy, establishing himself as an automation expert.

Potter and two other top officials were accused of knowingly putting workers' lives in danger during the 2001 Anthrax Attacks when letters containing anthrax spores were mailed through USPS. Laced letters targeting members of the Senate were processed at the Brentwood Post Office in Washington, D.C., where two postal workers died of anthrax inhalation and which had to be closed for decontamination.

In April 2002, Potter submitted the USPS Transformation Plan to Congress in response to the many challenges the Postal Service faced, such as new uses of technology. These challenges threatened the financial and commercial viability of the Postal Service. The Transformation Plan laid out short- and long-term options for change and was partial basis for the landmark Postal Reform And Accountability Act (H.R. 6407) in late 2006—the first postal reform since the Postal Reorganization Act of 1970.

On January 28, 2009, Potter testified before the Senate that if the Postal Service is not able to readjust their payment toward the pre-funding of retiree health benefits, as mandated by the Postal Accountability and Enhancement Act of 2006, the USPS would be forced to consider cutting delivery to five days per week during the summer months of June, July, and August.

H.R. 22, addressing this issue, passed the House of Representatives and Senate and was signed into law on September 30, 2009. However, PMG Potter has unveiled a plan to eliminate Saturday mail delivery. The universal service obligation and six day delivery are upheld by Congressional language within Appropriations legislation, so a reduction in service would require action from the House and Senate.

Chairman José Serrano (D-NY), of the House Appropriations subcommittee on Financial Services and General Government (which oversees language mandating six day service), said "While I understand the seriousness of the Postal Service's fiscal issues, I remain supportive of a six-day delivery schedule. I will be in conversations in coming weeks with the senior postal leadership and the postal unions in an effort to avoid service cuts."

On April 15, 2010, the House Committee on Oversight and Government Reform held a hearing to examine the status of the Postal Service and recent reports on short- and long-term strategies for the financial viability and stability of the USPS entitled "Continuing to Deliver: An Examination of the Postal Service's Current Financial Crisis and its Future Viability". At which, PMG Potter testified that by the year 2020, the USPS cumulative losses could exceed $238 billion, and that mail volume could drop 15% from 2009.