British motorcycle rider Mark Purslow died in qualifying for the Isle of Man TT races on Wednesday, organisers said in a statement.
The 29-year-old from Wales, in his second TT, had been on his third lap of the fourth qualifying session when the accident occurred at Ballagarey.
Purslow had earlier lapped the Mountain Course at an average speed of 120.86mph.
The races are being held again after a two-year absence due to the COVID-19 pandemic, the longest break for the event since World War Two.
Local rider Dave Moffitt was airlifted to hospital in Liverpool on Tuesday after another crash and was reported to be in a serious but stable condition.
The races around the island off the north-west coast of England have been run since 1907 and rank among the most dangerous in motorsport, with 259 fatalities in various events to date.