News of the cancellation comes days after the 71-year-old rocker cancelled two dates in Tokyo over the weekend after doctors instructed him to take "complete rest" over a suspected virus.
McCartney apologized to fans in a statement thanking them for their "kind messages" and expressing disappointment and sorrow for "letting [them] down."
Tour organizer Kyodo Tokyo said in a separate statement that McCartney "will regrettably have to cancel the remaining Japanese shows. Paul is still not feeling better and this cancellation is unavoidable."
The former Beatle is due to perform in Seoul, South Korea on May 28 and has 19 shows scheduled across the U.S. later on.