The demonstrators gathered near the tomb shouting "Bush go home", "Make peace, not war."
The noisy hecklers were close enough for Bush to hear them, but a string of Atlanta city buses encircling the tomb kept them out of the president's sight.
The president, accompanied by King's widow, Coretta Scott King, placed the wreath at the tomb and left without public comment.
In a statement released by the White House, Bush said "in remembering Dr King's vision and life of service, we renew our commitment to guaranteeing the unalienable rights of life, liberty and the pursuit of happiness for all Americans."
He reiterated that 19 January would be a national holiday in observation of King's memory.
King, born on 15 January, 1929 and a figurehead in the fight against racial discrimination, was assassinated by a sniper in April 1968.