The Holy Father is making the first papal visit to South Korea in 25 years.
After meeting the Korean head of state Francis will finish day one by meeting the country's bishops in Seoul.
On Friday more than 50,000 Catholics are expected to pack inside Daejoen World Cup Stadium for an open air mass.
Huge screens will be erected outside the ground to allow even more believers to watch the service.
The Pontiff will then meet families of the victims of the April 16 ferry disaster that killed more than 300 people.
Saturday will see Francis beatify 124 Korean martyrs after a tour in his pope mobile.
On the fourth day of his trip the Pope will visit Haemi Martyrdom Holy Ground where over 1,000 Roman Catholics were buried alive between 1866 and 1882.
He'll also hold the closing mass at the Asian Youth Day.
On Monday, the final day of his tour, Pope Francis will lead a mass for peace and reconciliation at the Myeongdong Cathedral in Myeong-dong, Seoul
North Korea had been asked to send representatives but declined.
During his journey the Holy Father flew over China and sent a message to the Chinese government.
It's customary for the Pope to send a telegram to every nation on his flight path.
It said: "Upon entering Chinese airspace, I extend best wishes to your excellency and your fellow citizens, and I invoke the divine blessings of peace and well-being upon the nation".