On December 12, 1799, Washington inspected his farms on horseback. He returned home late and had guests over for dinner. He had a sore throat the next day but was well enough to mark trees for cutting. That evening, Washington complained of chest congestion but was still cheerful. On Saturday, however, he awoke to an inflamed throat and difficulty breathing and ordered estate overseer George Rawlins to remove nearly a pint of his blood; bloodletting was a common practice of the time. His family summoned Drs. James Craik, Gustavus Richard Brown, and Elisha C. Dick. Dr. William Thornton arrived some hours after Washington died.

Dr. Brown initially believed Washington had quinsy; Dr. Dick thought the condition was a more serious "violent inflammation of the throat". They continued the process of bloodletting to approximately five pints, but Washington's condition deteriorated further. Dr. Dick proposed a tracheotomy, but the other physicians were not familiar with that procedure and therefore disapproved. Washington instructed Brown and Dick to leave the room, while he assured Craik, "Doctor, I die hard, but I am not afraid to go."

Washington's death came more swiftly than expected. On his deathbed, out of fear of being entombed alive, he instructed his private secretary Tobias Lear to wait three days before his burial. According to Lear, Washington died between 10 p.m. and 11 p.m. on December 14, 1799, with Martha seated at the foot of his bed. His last words were "'Tis well", from his conversation with Lear about his burial. He was 67.

Congress immediately adjourned for the day upon news of Washington's death, and the Speaker's chair was shroud in black the next morning. The funeral was held four days after his death on December 18, 1799, at Mount Vernon, where his body was interred. Cavalry and foot soldiers led the procession, and six colonels served as the pallbearers. The Mount Vernon funeral service was restricted mostly to family and friends. Reverend Thomas Davis read the funeral service by the vault with a brief address, followed by a ceremony performed by various members of Washington's Masonic lodge in Alexandria, Virginia. Congress chose Light-Horse Harry Lee to deliver the eulogy. Word of his death traveled slowly; church bells rang in the cities, and many places of business closed. People worldwide admired Washington and were saddened by his death, and memorial processions were held in major cities of the United States. Martha wore a black mourning cape for one year, and she burned their correspondence to protect their privacy. Only five letters between the couple are known to have survived: two from Martha to George and three from him to her.