The movie released this month is based on the true story of a Korean taxi driver and Jurgen Hinzpeter, a German journalist who covered the armed revolt.
Moon was accompanied by Edeltraut Brahmstaedt, the wife of Hinzpeter, and her family.
In May 1980, citizens of the southern city rose up against a military junta led by Chun Doo-hwan, an Army general, who assumed power via a coup after his predecessor President Park Chung-hee was assassinated.
Special operations forces cracked down on the protests leaving hundreds of citizens dead or missing.
|President Moon Jae-in (C) flanked by Edeltraut Brahmstaedt (L) and actor Song Kang-ho watch the movie "A Taxi Driver" at a movie theater in Seoul on Aug. 13, 2017. (Yonhap)|
Moon told Brahmstaedt most South Koreans were unaware of what happened in Gwangju due to the government's media censuring and that many journalists who tried to report about it were sacked during the authoritarian rule, according to the presidential office.
"We got to know the truth thanks to your husband," Moon was quoted as saying.
Brahmstaedt said her husband would have been "so pleased" with the movie about Gwangju, which was a large part of his life.
"The movie shows how a foreign reporter's efforts contributed to Korea's democratization," a presidential official said. "(The president) saw the film to honor Hinzpeter in respect for what he did for the country."
|This photograph, released by the May 18 Memorial Foundation on Aug. 10, 2017, is one of the pictures taken by Jurgen Hinzpeter during the nine-day pro-democracy uprising in Gwangju, some 329 km southwest of Seoul. (Yonhap)|
Hinzpeter, who passed away in May last year, is one of a few foreign journalists who exposed the military's bloody quelling of citizens. Upon Hinzpeter's will, part of his body has been enshrined in a special cemetery dedicated to the victims in Gwangju.
The film surpassed 7 million in attendance on Saturday, 11 days after its release, according to the film's distributor. (Yonhap)