Astro had been with the band since its founding in 1978 and left in 2013 to join the breakaway group UB40 with Ali Campbell.
In a statement, UB40 said they are "absolutely devastated and completely heartbroken."
"The world will never be the same without him," they said of their former bandmate. "We ask you to please respect his family's privacy at this incredibly difficult time."
Astro's most famous contribution to UB40 was penning the hit single Rat In Mi Kitchen, which he also sang lead vocals on.
Wilson earned the nickname Astro due to wearing a pair of Doc Marten boots with the word "Astronaut" emblazoned on them.
"Fortunately, no one called me astronaut because it is rather a mouthful so they shortened it to Astro and it has stuck ever since," he said in a 2016 interview.
Earlier this year Astro spoke with the Guardian about how UB40's early days were shaped by the hardship and injustice they faced.
"I went through the same rigmarole as most black people in the late 70s," he said. "We found it harder to write love songs than militant lyrics because it was a lot easier to write about stuff you had witnessed or read about. It seemed natural to us."
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