Event organizers confirmed the 52-year-old's death on Monday after "an incident on the final lap of the first Supersport Race."
"We extend our deepest sympathy to Davy's partner Trudy, his family, loved ones, and friends," a statement
"Davy was a stalwart of the TT paddock, with 2022 marking 20 years since he first competed in the Isle of Man TT Races. Today's Supersport Race was his 80th TT race start."
Every year, the Isle of Man is transformed into a motorcycle bonanza which was first held in 1907.
The event, which includes a number of races around the island in the Irish Sea, returned in 2022 after a two-year hiatus during the Covid-19 pandemic.
Organizers said Morgan had recently contemplated leaving the sport but decided to return after missing it during the pandemic.
He is now the third rider to be killed at this year's event following the death of 29-year-old Mark Purslow
and another driver last week.
Another competitor was also airlifted to hospital in critical condition.