Charles, 76, travelled to the Heaton Park Hebrew Congregation Synagogue in the Crumpsall district of Manchester to show support to those who had been affected by the attack, and the wider Jewish community.
Two men, Adrian Daulby, 53, and Melvin Cravitz, 66, were killed in the incident which took place during Yom Kippur, the holiest day in the Jewish calendar.
Monday's visit was the King's first official engagement since his younger brother Prince Andrew announced on Friday that he was giving up his titles and honours including being known as the Duke of York.
Andrew said he did not want the accusations against him, which include sex abuse allegations relating to his links to the late US sex offender Jeffrey Epstein which he still "vigorously denies," to distract from the work of the king and the other members of the family.
However, days later Andrew was still dominating the headlines and diverting attention from Charles' poignant trip to Manchester.
After the attack, Charles said was "deeply shocked and saddened" and during his visit to the synagogue he met some of those who had been inside when it took place.
Jihad al-Shamie, a 35-year-old UK citizen of Syrian descent, drove a car into pedestrians and attacked people with a knife before being shot dead by armed police.
The incident took place amid concern about rising levels of anti-Semitism in the United Kingdom.
Jews suffered the highest rate of religious hate crimes in England and Wales in the year to March, interior ministry data showed on Thursday.
