The Mad Scientist (also called Mad Scientist Monster) on The Masked Singer season 13 was country singer Brian Kelley , best known as one half of Florida Georgia Line.

Quick Scoop

  • The Mad Scientist Monster’s identity was officially revealed as Brian Kelley in the season 13 episodes in early May 2025.
  • He’s the former Florida Georgia Line member who has since moved into a solo country career.
  • Panelist Jenny McCarthy was the only judge to correctly lock in Brian Kelley as her final guess before the unmasking.

Clues that pointed to Brian Kelley

Fans and recap sites pieced the identity together from a series of themed clues.

  • References to a highly recruited athlete and “athlete-turned-singer” tied back to Brian’s baseball background before music.
  • Multiple nods to Florida (orange-tipped pen, Florida-related imagery) pointed at Florida Georgia Line.
  • Two bees on a badge hinting at “Meant to Be,” FGL’s hit with Bebe Rexha.
  • A clue about performing with someone from season 4 of The Masked Singer matched Florida Georgia Line’s collaboration with Backstreet Boys, whose member Nick Carter was Crocodile in season 4.
  • Talk of a duo splitting and going solo mirrored Florida Georgia Line’s breakup and Brian starting a solo career.

These clues, plus his country-leaning vocals and height, kept fans’ theories circling around country stars until the on‑air reveal confirmed Kelley.

TL;DR: If you’re wondering “who was Mad Scientist Masked Singer?” — it was Brian Kelley from Florida Georgia Line, unmasked in The Masked Singer season 13.

Information gathered from public forums or data available on the internet and portrayed here.