President Park was accorded an official welcome in Tehran on Monday on the first day of her three-day visit, heading South Korea's biggest-ever traveling business delegation of over 230 executives, Press TV reported.
The two presidents then sat for their first meeting since the establishment of diplomatic relations between the two countries in 1962.
Iranian and South Korean officials also signed 19 memorandums of understanding, IRNA reported.
Cabinet ministers and senior officials from the two countries signed the documents as part of efforts to boost the relations between Tehran and Seoul.
The deals are meant to boost bilateral collaborations in a range of fields, from maritime transportation to cultural and academic issues.
An extradition treaty was among the agreements signed in the ceremony.
Other MoUs were on cooperation in the oil, gas and petrochemical industry, management of water resources, technological interaction, medical fields and banking ties.
Peace on Korean Peninsula
Later in a joint news conference, Rouhani called for peace on the Korean Peninsula, saying Iran is opposed to the manufacturing of weapons of mass destruction of any kind.
He said Iran and South Korea are set to boost their trade volume from the current six billion dollars to $30 billion.
President Park called for further expansion of ties between Iran and South Korea in industrial, trade and cultural sectors.
South Korea has said it is eager to participate in Iran’s development projects and expand economic cooperation on communication technology, information, healthcare and culture.
South Korea has been a major importer of Iran’s crude oil. On Sunday, Minister of Petroleum Bijan Zanganeh said Iran's oil exports to South Korea have more than quadrupled to 400,000 barrels a day since sanctions were lifted in January.
Iran, whose exports to South Korea were less than 100,000 barrels a day before sanctions were lifted, has since worked to quickly boost its output. It has focused on selling to its traditional customers in Asia, but has also shipped cargoes to Europe.
Zanganeh also said Iran and South Korea were working to resolve difficulties in transferring payments for the oil sales.
World leaders have been visiting Tehran after the implementation of the nuclear agreement, dubbed the Joint Comprehensive Plan of Action (JCPOA), between Iran and the P5+1 group of countries in July 2015.
In a message on his Instagram account on Sunday, President Rouhani said Iran is open to foreign investment.
"Our economy will not get well unless we are able to attract investment," he said.
"Today, these conditions have been provided and the leaders which travel to Iran bring with them representatives of scores of important trading companies," Rouhani added.