What is the sexual orientation of Louis Smith?

It depends one which Louis Smith you're talking about:

Louis Smith (gymnast) (born 1989), British gymnast

Louis Smith (politician) (1879-1939), English politician

Louis Smith (Australian politician) (1830-1910), Australian politician

Lou Smith (1928-2007), American singer

Louis Carter Smith (1870-1961), Archery champion and historian

Louis Smith Tainter, for whom the Louis Smith Tainter House is named after

Louis Laybourne Smith (1880-1965), Australian architect

Louis Smith (musician) (born 1931), American jazz trumpeter

Louis S. Smith II, co-founder of Shindana Toys