Arthur Folasa Ah Loo, a fashion designer famous for appearing on “Project Runway,” was fatally shot at a “No Kings” protest over the weekend in Utah.

Police in Salt Lake City say Arthur was shot during Saturday’s demonstration … and he was rushed to a hospital, where he ultimately died from his injuries.

Based on a preliminary investigation, cops say Arthur was not the intended target of gunfire and appears to have been an innocent bystander.

Cops say Arthur was hit when two men opened fire on a man they say was brandishing an AR-15 style rifle at protesters … and it sounds like Arthur was in the wrong place at the wrong time.

Police say the men who allegedly opened fire told officers they were “part of the event’s peacekeeping team.”

SLCPD says they were told 24-year-old Arturo Gamboa was the man wielding the rifle … and he was taken to a hospital with a gunshot wound and was later booked into the Salt Lake County Metro Jail on a murder charge.

Cops say they are still investigating the shooting, including the alleged “peacekeepers.”

Arthur competed on “Project Runway” in 2019.

He was only 39.