The will reportedly divides Jackson's immense estate among his mother, three children and one or more charities, but does not name his father, Joe Jackson, according to people close to the late singer.
The singer died suddenly last Thursday at the age of 50. His parents, who filed Monday for, have suggested a will might not exist.
According to the Journal's report, the 2002 document names lawyer John Branca and veteran music executive John McClain as executors. Branca, who authored the will, was Jackson's main attorney from 1980 to 2006, and was rehired by Jackson the week before he died. Neither Branca nor McClain could be reached by the newspaper for comment.
People familiar with Jackson's finances told the Journal that the singer died with something in the region of $500 million in debt, but that his estate is likely worth an even greater sum - possibly $200 million more than he owed.
No confirmed legal will has surfaced yet for the global star, but the celebrity news Web site TMZ.com reported Monday that Jackson's lawyer has a copy of a will and he intends to file it with the court.
Jackson never told his family who he had in place to handle his business affairs, a person close to the family has told The Associated Press. The person, who requested anonymity because of the delicate nature of the situation, said they were told by the singer's phalanx of advisers that he likely had a will, but it may be many years old.