The 32-year-old former national captain and Manchester United star said he had been in a relationship with presenter Kim Min-Ji, 27, for several months.
Park enjoys superstar status in South Korea and his personal life has always been a subject of intense speculation.
On Wednesday, a local newspaper published a picture of Park and Kim walking arm-in-arm in the rain along the bank of Seoul's Han River.
"I had planned to make a surprise announcement that I am passionately in love with her and devoted to her, but now I guess I only need to confirm last night's report," Park joked.
Park said the couple had met each other's parents, but stressed there had been "no talk" of a wedding date so far.
Kim co-hosts a weekly football highlights programme.
Park played a key role in taking South Korea to the 2002 World Cup semifinals, after he which he followed the national coach Guus Hiddink to the Dutch club PSV Eindhoven.
He signed with Manchester United in 2005 and won four English Premier League and one Uefa Champions League winners medals.
He joined Premier League side Queens Park Rangers before the 2012-2013 season, but the side were relegated in May.
He retired from international football in January 2011.