The King met train guard Samir Zitouni, who was hailed a hero in the wake of the Huntingdon attack, during a special reception at Buckingham Palace on Wednesday evening.
Charles was pictured shaking hands with Mr Zitouni, who was seriously injured as he stepped in to protect passengers as they were being stabbed on the Doncaster to London train service.
Mr Zitouni, known as Sam to friends, attended the reception with his wife Eleni Sakkoulei and other members of the public and railway staff who showed exceptional bravery during the attack in Cambridgeshire on November 1.
The King was also pictured meeting LNER train driver Andrew Johnson, who previously served in the Royal Navy, and his partner Abbie Northfield.
Anthony Williams, 32, is charged with 10 counts of attempted murder over the Huntingdon incident.
He is also charged with possession of a bladed article on November 1, and several other offences in the hours preceding the attack on the train.
He remains in custody pending further court hearings scheduled for next year.
