Jackson had asked to testify by a video link from the United States because of an unspecified illness. But his lawyer Robert Englehart informed the court on Thursday that Jackson's doctors had cleared him to travel in two days' time.
Jackson is scheduled to testify on Monday.
Sheik Abdulla bin Hamad Al Khalifa , the second son of the king of Bahrain, claims that Jackson reneged on a contract for an album, a candid autobiography and a stage play, after accepting millions in advances.Jackson says the money was a gift.
The case is being tried in London by mutual agreement, Al Khalifa's representatives have said. It is due to wrap up by the end of the month.
The singer's finances fell apart following his arrest in 2003 on charges that he molested a 13-year old boy at his Neverland ranch in the U.S. He moved to Bahrain after being acquitted.