Police were called to the property in West Main Street at around 3:30pm after a 30-year-old man was found within.
His death is currently being treated as unexplained pending the outcome of a post mortem and next of kin have been informed.
A 49-year-old male has now been arrested and he is expected to appear before Livingston Sheriff Court on Thursday, December 29th.
Officers are not looking for anyone else in connection with this incident however there will be additional high visibility patrols within the area to provide reassurance.
A spokesman said: “Officers were called to a property in West Main Street at around 3:30pm following a report of concern for the male occupant. “Sadly, the man was pronounced dead at the scene by paramedics.”
Police Scotland is appealing for any person who may have information relevant to the onging inquiry to contact them on 101. Alternatively, an anonymous report can be made to the charity Crimestoppers on 0800 555 111.