Carmarthenshire-born Gareth Hughes, who died in 1965, later gave up his A-list Hollwood life to be a church minister to a tribe of native Americans.
Kelvin Guy, a relative on his Hughes' grandmother's side, unveiled a blue plaque at 38 Princess St, Llanelli, where Hughes was living, aged six.
It comes 10 years after a bronze plaque was unveiled in Parc Howard Museum.
That plaque was unveiled by Hughes' niece Nansi Howells and Hughes biographer Stephen Lyons.
Mr Lyons said Hughes was largely forgotten despite being an "immense" figure, becoming a star on stage in America before moving into the nascent Hollywood film industry.
He said: "You have your famous Welsh actors and famous Welsh ministers but here you have someone who had such an overriddingly varied life.
Hughes, born in Dafen, Carmarthenshire in 1894, is said to have walked to London as a teenager to join a theatre company of Welsh actors, although Mr Lyons said he could find not any record of that in his research.
On tour in America, Hughes went on to receive rave reviews, becoming a favourite of JM Barrie, before going into films and making a fortune which he later lost in the Wall Street Crash.
Mr Lyons said: "He was known as the Metro Boy boy stars - for Metro Pictures which later became Metro Goldwyn Mayer.
"He had a town house, a chauffeur, a groom for his horses. He lived quite well.
"He had all the trappings of a star but although he was a star in Hollywood, he never became an international star such as Douglas Fairbanks, Mary Pickford or Charlie Chaplin.
"And he didn't continue his careeer. He genuinely got God. He became a Protestant Episcopalian minister."
Mr Lyons said Hughes is still fondly remembered by the Paiute people to whom he ministered in later life.
"He had an immense impact on them and is remembered above all ministers."
In 2008, Mr Guy, from Burry Port, made a documentary, Desert Padre, about his relative's life and work.
A plaque honouring a silent-era Welsh film star-turned-missionary has been unveiled at a house where he was a boy.