Question: Matt McNamara was portrayed on the series Nip/Tuck by which American actor?

Context articles: Nip/Tuck
List of Nip/Tuck episodes
Julia McNamara
Nip/Tuck: Original TV Soundtrack
Christian Troy
John Hensley
Matt McNamara
Sean McNamara (Nip/Tuck)
Marlowe Sawyer
Dylan Walsh

Nip/Tuck is an American television drama series created by Ryan Murphy; it aired on FX in the United States from July 22, 2003 to March 3, 2010.
 The series focuses on "McNamara/Troy", a cutting-edge, controversial plastic surgery center—but, particularly its founders: Drs. Sean McNamara and Christian Troy (portrayed by Dylan Walsh and Julian McMahon).
 Each episode featured graphic, partial-depictions of the plastic surgeries of one or more patients (who requested both popular [e.g., breast augmentation] and exotic [e.g., "vaginal rejuvenation"] procedures—as well as removals of obscure skin diseases).
 Much of the series' drama is derived from the tumultuous personal lives of its main characters (including the doctors' loved ones).
"Nip/Tuck" is an American drama created by Ryan Murphy, which aired on FX in the United States between 2003 and 2010.
 The series focuses on McNamara/Troy, a plastic surgery practice, and follows its founders, Sean McNamara and Christian Troy (portrayed by Dylan Walsh and Julian McMahon).
 Each episode typically involves the cosmetic procedures of one or more patients, and also features the personal and professional lives of its main cast.
Julia McNamara ("née" Noughton) is a fictional character in the American television series "Nip/Tuck", portrayed by Joely Richardson.
The soundtrack of the Emmy and Golden Globe award-winning American television medical drama series Nip/Tuck created by Ryan Murphy for FX Networks was mixed by the DJ duo Gabriel & Dresden and the collaborations of other artists.
Dr. Christian Troy is a fictional character played by Julian McMahon on the FX Networks series "Nip/Tuck".
 The show revolves around McNamara/Troy, the plastic surgery practice he runs with his business partner and best friend, Sean McNamara.
John Carter Hensley (born August 29, 1977) is an American actor, best known for his role as Matt McNamara on "Nip/Tuck".
Matthew "Matt" McNamara is a fictional character on the American television series "Nip/Tuck", portrayed by John Hensley.
Dr. Sean McNamara is a fictional character on FX Networks' drama series "Nip/Tuck", portrayed by Dylan Walsh.
 His character opens the show with the trademark catchphrase, "Tell me what you don't like about yourself."
 His partner, Christian Troy, has been his best friend since attending college together at the University of Miami, which is partly why they went into business together.
 Sean is portrayed as the more skilled, yet more troubled surgeon, who apparently specializes in craniofacial surgery.
 He is often plagued by family distresses involving his wife Julia and son Matt.
 The two also have a daughter, Annie, and a newborn son named Conor.
Marlowe Sawyer is a fictional character in the television series Nip/Tuck.
 Marlowe Sawyer is portrayed by Peter Dinklage in the television series.
Dylan Walsh (born Charles Hunter Walsh: November 17, 1963) is an American actor.
 He is best known for his role as Dr. Sean McNamara in the FX television series "Nip/Tuck".