The Pontiff has clashed with the US leader on climate change and the treatment of immigrants and refugees
So things might get awkward when the blustering American president and the soft-spoken pontiff touch base.
Here are some of the issues they have disagreed on:
Without mentioning Mr Trump by name, the Pope heavily criticised the President’s promise to build a border wall and “make Mexico pay for it” in February. In remarks at the Vatican, he said it was a Christian’s calling “to not raise walls but bridges, to not respond to evil with evil, to overcome evil with good”.
He continued to seemingly address Trump, saying: “A Christian can never say: ‘I’ll make you pay for that.’ Never! That is not a Christian gesture. An offence is overcome with forgiveness, by living in peace with everyone.”
The Pope’s comments follow a very public spat last year. Francis seemed to criticise Mr Trump during the 2016 campaign for his positions on immigration, suggesting that his policies made the US leader “not Christian”. Mr Trump described this as “disgraceful”.
The Pope started the beef while flying back to Rome from Mexico in February 2016. “A person who thinks only about building walls, wherever they may be, and not building bridges, is not Christian,” he said.
Mr Trump quickly responded at a rally, telling the crowd: “For a religious leader to question a person’s faith is disgraceful.”
He added: “No leader, especially a religious leader, has the right to question another man’s religion or faith.” The now-President then accused the Mexican government of “using the pope as a pawn”.
Mr Trump also attempted to implement two travel bans early in his administration, which the Vatican called troubling.
The pope has favoured a message of inclusiveness and integration for immigration.