"When the Rio Olympics ended, I thought the next Olympics four years later were too far off," Park told reporters ahead of this week's Doosan Match Play Championship in Chuncheon.
"I doubted whether I could be still active until then. But as the next Olympics is getting closer, I think it is worth a try."
Park, 30, regained the number one spot in the Ladies Professional Golf Association (LPGA) rankings in April this year but is now in sixth place.
The top 15 players in the rankings automatically qualify for the Olympics with a limit of four golfers per country. Park is the third-highest ranked South Korean behind world number one Ko Jin-young and number three Park Sung-hyun.
"I know making it to the national team is harder than winning the Olympic gold," Park added.
"I must be very happy and pleased to have a chance to play at the Olympics and defend my title."
The Olympics get underway in Tokyo on July 24 next year.
(Reporting by Rohith Nair in Bengaluru, editing by Nick Mulvenney)
