What was Prince's last studio album released before his death?

Prince's last studio album released before his death was Hit n Run Phase Two.

The album first appeared on December 12, 2015, as an exclusive release on the Tidal streaming service, less than five months before Prince died. It was the second part of a planned two-album sequence, following Hit n Run Phase One, which had been released earlier in 2015.

Hit n Run Phase Two is Prince's thirty-ninth studio album and features a more organic funk and soul sound than some of his preceding electronic-heavy work. The recording includes a large brass ensemble known as the NPG Hornz. Its track list also includes “Baltimore,” Prince's response to the death of Freddie Gray and the protests that followed.

The album's physical CD release can cause confusion: a limited CD was distributed to concert attendees in early 2016, while a worldwide retail CD release arrived on May 6, 2016, after Prince's death. Thus, the answer refers to the album's original release during his lifetime, not later posthumous compilations or archival releases.