Father John X. Halligan was a protagonist in the 1952 movie When in Rome.
A Roman Catholic priest, Halligan went to Rome for the 1950 Holy Year. While en route to Rome, Halligan came across a man named Joe Brewster. Brewster was an escaped convict wanted by American law enforcement. Brewster stole Halligan's clothing and identity, convincing other priests there that he was Fr. Halligan.
The Italian authorities soon found the real Fr. Halligan. Convinced of his identity, the Italians assured Fr. Halligan that they would find and arrest Brewster.
Meanwhile Halligan found Brewster on his own, who got the idea in his head that he could make things right with God if he went on a pilgrimage to the five major basilicas of Rome. Halligan told him that it wouldn't be that simple, that he needed to confess his sins first and face the music for his crimes. After hearing Brewster's first confession in over two decades, Halligan and Brewster set out to visit each of the five major basilicas in Rome and Vatican City, with Halligan helping Brewster evade arrest long enough to complete his pilgrimage.
While avoiding the authorities the pair eventually came across a monastery which housed a religious order where the monks never speak to anyone except their superiors. During their brief visit Brewster was drawn to the place. Soon the two men leave to complete Brewster's pilgrimage, but become separated. Halligan convinced the police to let Brewster finish his pilgrimage before arresting him, and they took him in to custody after he visited St. Peter's Basilica.
The news comes a short time later that Brewster escaped. The news is a serious blow to Fr. Halligan, who had honestly thought that Brewster had reformed himself. While retracing his steps he came across the monastery visited earlier. There he found Brewster living as a monk with the blessing of the abbot. Assured of the good intentions of Brewster, Halligan took his leave of Brewster, assuring him that he would visit in 1975 when the next Holy Year took place.
Feeling much better about his abilities, Halligan left the monastery, and joined a procession of Catholic faithful as they made their way to the Vatican.
- John X. Halligan was played by Van Johnson.