Johnson St. Louis, 21, was shot several times just before midnight Wednesday on the 800 block of Southeast Second, north of Linton Boulevard and west of Dixie Highway.
Paramedics took St. Louis to Delray Medical Center, where he died of his injuries, according to city police.
City police said they arrested a 15-year-old at an unknown address in Delray Beach with the assistance of U.S. Marshals.
The Palm Beach Post does not name juveniles accused of a crime unless they are charged as adults. The Palm Beach County State Attorney s Office will decide whether to bring adult charges against the 15-year-old.