Nick “Blue Collar” Klein was born on September 8, 1995, in Plymouth, Wisconsin. Raised in a working‑class environment, he cultivated a strong wrestling base from high school before transitioning into Brazilian Jiu‑Jitsu and striking disciplines. He developed his foundational grappling skills through regional training in Wisconsin and continued sharpening his craft at Pura Vida BJJ & MMA, where he remains affiliated.
Klein embarked on his professional MMA journey in June 2021, debuting at Pure Fighting Championships 19 with a first‑round TKO in just 29 seconds. Over the next year, he secured back‑to‑back quick stoppages—including a 17‑second TKO in February 2022 and a unanimous decision win at LFA 131 in May. Though he suffered a setback by TKO in mid‑2022, Klein rebounded with consecutive submission victories: first via rear‑naked choke in Ignite Fights No Mercy 11, then in the main event of MCC 69 with another choke finish.
In October 2024, Klein accepted a short‑notice bout on Dana White’s Contender Series and delivered one of the fastest finishes that season—submitting Heraldo Souza in just 37 seconds to earn a UFC contract. Known for his efficiency and gritty approach, Klein carries a 6‑1 pro record with five finishes to date. His methods reflect a straightforward mindset: train hard, strike when it matters, and back it up with disciplined execution. With that earned opportunity, he stepped into the UFC middleweight ranks, ready to climb with consistent, calculated performances.