*** FYI: NOT TO BE CONFUSED WITH ACTOR BILLY GILBERT (born William Gilbert Barron) WHO LIVED FROM 1894 TO 1971. ***
Billy Gilbert (born William V. Campbell; September 15, 1891—April 29, 1961) was involved in more than 150 American films between 1913 and 1936, working as either an actor, extra, or director. Gilbert spent his entire career working almost exclusively in shorts, often uncredited.
[biography (excerpted) from Wikipedia]

Whispering Whiskers
1926 · as Indian

Making a Living
1914 · as Jealous Husband (uncredited)

Those Country Kids
1914 · as Man whose Carriage is Stolen

Mabel's Strange Predicament
1914 · as Bellboy (uncredited)

Hayfoot, Strawfoot?
1926 · as Doctor

Caught in a Cabaret
1914 · as Cabaret Patron (uncredited)

Tillie's Punctured Romance
1914 · as Policeman (uncredited)

The Rounders
1914 · as Doorman in Blackface

The Masquerader
1914 · as Cameraman

Noisy Neighbors
1929 · as Third Son

Tango Tangles
1914 · as Guest in Cowboy Hat (uncredited)

His Bitter Pill
1916 · as Barfly

A Hash House Fraud
1915 · as Freeloading Customer

Never the Twins Shall Meet
1932 · as Mr. Clark

Ambrose's First Falsehood
1914 · as Café Patron

A Busy Day
1914 · as Policeman

Fatty Joins the Force
1913 · as Fighter

Those Love Pangs
1914 · as Movie Patron