The father of Clifford and Alexander, Arthur Widmore is the CEO of the Widmore Corporation, though he leaves day to day operations for Cliff to deal with. He is obsessed with his Scottish Heritage, and throughout the book comments about the greatness of his ancestry. He also enjoys alcohol, particularly Scotch whisky. Clifford describes his father as senile, failing both physically and mentally.
Arthur has been married three times. His first wife was the mother of Clifford and Alexander. After her death, he married again, but the relationship ended (for unknown reasons). He then remarried at St. Barts Church, this time to Vivian Widmore, seen by many as a gold digger out for the Widmore fortune. The two have been married 5 years in the book's present.
- The combination to the gate outside of the Widmore estate is 8-1-5-1-6, the dates of the twins' birthdays (they were born around midnight).
- Fancy watches (Rolex watches?) were stolen from his estate.