William Duffy is an actor, known for The West Wing (1999), It's Always Sunny in Philadelphia (2005) and Scandal (2012).
NCIS - Season 16
ER - Season 2
Its Always Sunny in Philadelphia - Season 13
ER - Season 10
Bosch - Season 3
ER - Season 3
The Division - Season 2
ER - Season 5
California Dreams - Season 5
The Mentalist - Season 4
Heroes - Season 3
Heroes - Season 1
Blast from the Past
Its Always Sunny in Philadelphia - Season 1
The Mentalist - Season 6
The Big C - Season 4
Its Always Sunny in Philadelphia - Season 7
The Big C - Season 2
ER - Season 14
Waist Deep
Scandal - Season 5
California Dreams - Season 2
Bosch - Season 4
ER - Season 15
Hearts Afire - Season 1
Its Always Sunny in Philadelphia - Season 4