He admitted guilt to two charges of conspiring to provide support to terrorists and conspiring to murder, kidnap, maim and injure people. Prosecutors agreed to dismiss several other counts against him.
Boyd, 40, did not comment during the hearing except to answer yes-or-no questions from the judge. He was tearful, and his beard had been shaven clean.
Two of Boyd's sons are among several other people charged in the case. The FBI has said agents seized some two dozen guns and more than 27,000 rounds of ammunition from Boyd's home south of Raleigh.
"North Carolina and the United States are safer now that Daniel Boyd is no longer in a position to plot against us. His admission of guilt today proves to the world he intended to carry out violent jihad, which our evidence against him has shown. This should send a signal to any who may share Boyd's extremist ideology - the FBI and our law enforcement partners won't back down in our fight to stop the next attack," said Joseph S. Campbell, Acting Special Agent in Charge of the FBI in North Carolina in a statement.
At sentencing, set for May, Boyd faces up to 15 years imprisonment followed by up to three years supervised release for conspiring to provide material support to terrorists and up to a life term of imprisonment followed by up to five years of supervised release for conspiring to murder, kidnap, maim, and injure persons in a foreign country.
"This case proves how our world is changing. Terrorists are no longer only from foreign countries but also citizens who live within our own borders. We must protect our homeland. I am committed to using any and all legal means to take on the challenge of finding and prosecuting others with similar radical views who plot violent attacks," U.S. Attorney George E.B. Holding commented.