The Speaker of the House who presided over the largest increase in the national debt is Nancy Pelosi. During her tenure as Speaker, the federal debt increased by approximately $9.6 trillion. This significant rise in debt occurred over her two terms as Speaker: first from January 2007 to January 2011, and then from January 2019 to January 2023 [oai_citation:1,In 2,000 Days as Speaker, Pelosi Has Increased Debt a Record $9.6 Trillion](https://townhall.com/columnists/terryjeffrey/2020/06/24/in-2000-days-as-speaker-pelosi-has-increased-debt-a-record-96-trillion-n2571203) [oai_citation:2,PolitiFact | Fact-checking new House Speaker Mike Johnson on the federal debt](https://www.politifact.com/factchecks/2023/oct/26/mike-johnson/fact-checking-new-house-speaker-mike-johnson-on-th/).
Under Pelosi's leadership, the debt increased at an average rate of approximately $4.8 billion per day. Her tenure saw a combination of increased spending due to the Great Recession and the COVID-19 pandemic, contributing to this substantial rise in the national debt [oai_citation:3,In 2,000 Days as Speaker, Pelosi Has Increased Debt a Record $9.6 Trillion](https://townhall.com/columnists/terryjeffrey/2020/06/24/in-2000-days-as-speaker-pelosi-has-increased-debt-a-record-96-trillion-n2571203).