Delegates chanted: "Hillary, Hillary" as US Senator Barbara Mikulski of Maryland put Clinton's name forward for a state-by-state roll call at the Democratic convention in Philadelphia.
"Yes, we do break barriers, I broke a barrier when I became the first Democratic woman elected to the Senate in her own right," Mikulski said. "So it is with a full heart that I'm here today to nominate Hillary Clinton to be the first woman president," Mikulski said.
After a long battle with US Senator Bernie Sanders, Clinton has more than the 2,383 delegates needed to win the vote and be the party's standard-bearer against Republican nominee Donald Trump in the Nov. 8 election.
Sanders has endorsed Clinton, a former secretary of state, but some of his supporters have protested in Philadelphia against the party leadership's apparent backing of her during the bitter Democratic primary fight.
The nominating process on Tuesday was expected to take about two hours. Sanders' name was also put forward for nomination but he does not have enough support in the convention hall to win despite his appeal to the young and liberal Democrats.
Supporters of Clinton, who was also a US senator and first lady to President Bill Clinton, say her Washington credentials show she has the experience needed for the White House during troubled times as the United States tries to speed up its economic recovery and faces security challenges abroad.
Detractors view her as too cozy with the establishment and say she carries political baggage dating back to the start of her husband's first White House term in the 1990s.
Hillary Clinton struggled to shake off Sanders during the Democratic state-by-state nominating contests, partly because of the controversy over her use of a private email server for official business when she was America's top diplomat from 2009 to 2013.