Park will manage his first match for the club when Hanoi play Binh Dinh at home in the 11th round of the top-flight V. League 1 on April 28.
Park, 48, is a former national player who made six appearances for the South Korean team and took part in the Summer Olympic Games 1996. He started his coaching career in 2009, two years after retiring. Before Hanoi, Park coached teams in China like Tianjin Quanjan and Tianjin Tianhai.
He finished his two-week quarantine in Vietnam on April 10.
This is the second time that Hanoi are changing managers this season after sacking Chu Dinh Nghiem and replacing him with former national team coach Hoang Van Phuc just this month.
The five-time V. League champions have not been in good form this season with injuries and unstable performances from key players. They are currently standing eighth with 13 points after 10 games and are in danger of falling out of contention for the championship.
After 13 rounds, V. League 1 will enter its second phase when only the top six teams will play each other for the crown. The other eight teams will play each other to avoid relegation. The new format was adopted after the Covid-19 crisis disrupted the tournament.