The 23-year-old, who previously played under Rovers boss Tony Mowbray while on loan at Coventry in 2015, has signed a three-year contract at Ewood Park.
He scored six goals during that spell and has also been on loan at Ipswich, where he ended last season, Colchester, Dagenham & Redbridge and Gillingham.
He made 11 league appearances for Reading, scoring twice.
One of those goals was scored against Blackburn last season.
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Blackburn Rovers have completed the signing of striker Dominic Samuel from Reading for an undisclosed fee.