The 1848 Democratic National Convention was a presidential nominating convention that met from Monday May 22 to Friday May 26 in Baltimore, Maryland. It was held to nominate the Democratic Party's candidates for President and Vice president in the 1848 election. The convention selected Senator Lewis Cass of Michigan for President and former Representative William O. Butler of Kentucky for Vice President.
As incumbent Democratic President James K. Polk declined to seek re-election, the Democratic Party nominated a new presidential candidate for the 1848 election. The major competitors for the presidential nomination were Cass, Secretary of State James Buchanan of Pennsylvania, and Supreme Court Justice Levi Woodbury of New Hampshire. Cass led on the first presidential ballot, and he continued to gain delegates until he clinched the nomination on the fourth ballot. Butler won the vice presidential nomination on the second ballot, defeating former Governor John A. Quitman of Mississippi and several other candidates. The Democratic ticket was defeated in the 1848 election by the Whig ticket of Zachary Taylor and Millard Fillmore.