Webb's interest in the job was widely known; he made a pitch to the committee on Dec. 10 in Orlando, Fla.
"I am running because I believe this historic election for chair will determine the future of our party," Webb said.
Webb was mayor from 1991 to 2003 after serving as a state legislator and Denver city auditor.
Others interested in the Democratic chairmanship include former presidential candidate Howard Dean; former Michigan Gov. Jim Blanchard; defeated Rep. Martin Frost of Texas; and Harold Ickes, who was an adviser to former President Clinton.
The current chairman, Terry McAuliffe (search), is not seeking another term.