Throughout most of the meeting, Pope Francis maintained a serious face - and thus provoked a barrage of Twitter jokes about Trump's first encounter with a Pope who has frequently criticized some of his policies.
The mood eventually lightened after the two exchanged gifts.
Here are some of the most memorable photos from the visit:
Trump and Pope Francis concluded the visit by wishing each other "good luck." On-scene reporters said the visit went by quickly and smoothly.
After the visit, Trump tweeted that he took the Pope's words to heart and was "more determined than ever to pursue PEACE in our world."
On their visit, Melania and Ivanka Trump wore traditional long black veils in keeping with Vatican protocol. While in Saudi Arabia over the weekend, both women skipped the traditional headscarves and dressed in Western clothes.
"I signed it personally for you," Pope Francis said as he handed Trump the copy of his peace talk. Trump gave the Pope a first-edition set of Martin Luther King Jr.'s writings.
In what many saw as a nod to Trump's tough stances on immigration and climate change, Pope Francis gifted Trump a signed copy of his speech at the last World Peace Summit and his 2015 encyclical letter on climate change.
Pope Francis broke the serious mood by hinting at Trump's large physical size. "What do you feed him on, Potica?" he asked the First Lady in reference to a calorie-heavy cake from her native Slovenia.
In the past, the Pope has frequently criticized Trump's tough approach to immigration — even, at one point calling those who build walls "not Christian."
The somber mood of the meeting was quickly picked up by Twitter commenters, who joked at Pope Francis' serious look.
Then Trump and Pope Francis went into a private study. Reporters present on the scene said Pope Francis did not smile when Trump called meeting him "a great honor."
In the early morning, Trump's motorcade arrived at the doors of the Vatican. Pope Francis welcomed the president inside, and the two shook hands.
On May 24, Pope Francis welcomed Trump and his family to the Vatican.