Solomon Finau is Rebecca Black's husband, the son-in-law of Billy and Sarah Black, and brother-in-law of Jacob and Rachel Black.
Biography
Solomon married Rebecca right after she turned eighteen and moved to Hawaii to live with him, partly to escape the memories of her deceased mother still lingering in La Push.
Solomon is a Samoan surfer who travels around the world to compete, and, like his wife, he knows nothing about the existence of vampires or the heritage of her tribe.
Note
His name and background story was never fully explained in the books, but his name was presented on the Black family tree in The Twilight Saga: The Official Illustrated Guide.