More than 220,000 people have RVSP'd on the event's official Facebook page. The National Park Service application, however, only estimated 25,000 people would attend the event, which is scheduled to last from noon to 3 p.m.
The rally is billed as a chance for people to voice their frustrations with American politics and the media, and, of course, be entertained.
Jon Stewart continues to insist that this is not a political rally, telling CNN's Larry King that the event is simply about delivering satirical comedy.
But many in politics and the media say this rally, which is scheduled to take place just days before the mid-term election, goes beyond the normal comedy delivered by Stewart and Colbert.
Stewart has said that they planned the day of the rally because it coincided with the show's broadcasts in Washington, D.C., not because of the midterm election. But even Stewart's broadcast in D.C. has added to the speculation about the importance of politics in Saturday's rally.
"The Daily Show," which has been taping in Washington, D.C. all week, took on a decidedly more political tone Wednesday night when President Obama sat down for a 30-minute interview with Stewart.
The interview had a slightly more serious tone than Stewart's usual broadcasts, as he pushed Obama on the campaign promises of hope and change, and the tough realities of office.
"When I say that when we promised during the campaign, change you can believe in, it wasn't change you can believe in in 18 months," Obama said. "It was change you can believe in, but you have to work for it."
While Stewart might not view himself as political figure, even the White House commented yesterday on Stewart's political heft with a certain section of voters. White House spokesman Robert Gibbs said that show is an ideal place to reach young people.
"The president hasn't been shy about going to the places where people are getting their information and trying to make his case," he said.
Our question to you today: Stewart and Colbert Set to Hold Rally Tomorrow: Simply Comedy or Larger Political Statement?
ABC News' Huma Khan contributed to this report.