Jackson, 47, of Chicago, wept quietly as he entered the plea in U.S. District Court in Washington, where Judge Robert Wilkins accepted the plea.
“Guilty, your honor. I misled the American people,” Jackson said after the judge asked his plea.
Under an agreement with prosecutors, Jackson faces up to five years – the maximum prison sentence allowed by law.
Wilkins scheduled sentencing for June 28.
Jackson’s father, Jesse Jackson Sr., sat in the front row of a courtroom filled with family, friends and reporters during the hour-long hearing on Wednesday.