Vedder canceled when he postponed his 15-city U.S. solo tour because of nerve damage in his right arm stemming from a back injury earlier this year.
Buffett is a Jazz Fest veteran who has built an empire based largely on such Caribbean-flavored rock hits as " Margaritaville." He first performed at Jazz fest in 1989.
This time, Buffett will leave his rock band behind and sing and play acoustic guitar with Mac McAnally, a Mississippi native named the Country Music Association's Musician of the Year for the past four years in a row.
Jazz Fest spans two weekends, April 27-29 and May 3-6.