Thomas is the Archbishop of Canterbury and the former Chancellor of England. He returns from exile to face intense political and spiritual hostility stemming from his refusal to submit ecclesiastical authority to royal jurisdiction. He possesses a deep religious devotion that clashes with his past life as a powerful earthly statesman, forcing him to weigh his spiritual convictions against his physical safety and personal pride.

The Chorus consists of the poor, working-class women of Canterbury. They act as a collective voice representing the common people who lack political power and are continuously subjected to the rules of the wealthy, the landowners, and the crown. They rely heavily on their faith to endure the hardships of their daily lives and dread the impending violence they sense in the air.

The Knights act as a collective physical threat and serve as avatars of worldly, secular power. They arrive heavily armed and belligerent, claiming to carry out the direct orders of King Henry II. They operate as a violent counterbalance to the quiet religious devotion found within Canterbury Cathedral.

King Henry II is the King of England and a former close friend to Thomas Becket. Though he never physically appears on stage, his presence looms heavily over the narrative. He demands absolute secular authority over his country, including the Church, creating the central dispute with the Archbishop.

The First Tempter is an old associate of Thomas Becket and King Henry II. He appeals to Becket's past memories, urging the Archbishop to abandon his feud and return to a life of comfort, safety, and friendship with the monarch.

The Second Tempter focuses entirely on earthly power and political influence. He argues that Becket's religious position lacks the tangible authority he once held, encouraging the Archbishop to reclaim the chancellorship and exert real control over the kingdom.

The Third Tempter represents a faction of rebellious, middle-class barons. He proposes a direct political alliance with Becket to overthrow King Henry II's rule, offering an earthly and violent solution to the Archbishop's struggle.

The Fourth Tempter offers the most dangerous argument to Thomas Becket. Rather than earthly power, he tempts the Archbishop with the glory of martyrdom itself, forcing Becket to question whether his spiritual devotion is actually driven by vanity and a desire for eternal fame.

The First Priest is a dedicated member of the Canterbury clergy. He worries intensely about the political danger surrounding Thomas Becket's return to England and fears for the safety of both the Archbishop and the broader Church.

The Second Priest is an optimistic and protective member of the clergy. He dismisses the anxious warnings of the Chorus and strongly believes that Thomas Becket's return will guide the common people through their ongoing hardships.

The Third Priest takes a highly philosophical and patient view of the unfolding crisis. He advises his peers to wait and observe the consequences of Thomas Becket's return, acknowledging that good and evil are difficult to parse immediately.

Reginald Fitz Urse acts as the First Knight representing King Henry II. He takes an aggressive lead in demanding that Thomas Becket and his servants immediately leave the country to face royal justice.

William De Traci acts as the Second Knight in the royal party. He insists that the group's violent approach is driven strictly by their official duty to the crown rather than personal malice.

Hugh De Morville is the Third Knight sent to discipline Thomas Becket. He views the Archbishop as a traitor who betrayed King Henry II's trust after being given the dual authority of Chancellor and Archbishop.

Richard Brito is the Fourth Knight acting on behalf of King Henry II. He holds intense animosity toward Thomas Becket, viewing the Archbishop's steadfast religious defiance as an act of massive egotism and madness.