Dr. William "Will" Zimmerman is a main character and male lead of the Canadian fantasy-science fiction television series Sanctuary.

Will is introduced in the series as an FBI's Behavioral Analysis Unit forensic psychiatrist, who was recruited by Helen Magnus (Amanda Tapping), head of the Sanctuary Network, to become her recent protégé.

[1] One of his known ancestors was Jack Zimmerman (Dunne), who served in the United States Army and was killed in action in Normandy during D-Day in 1944.

He is later recruited by Helen Magnus to join her Sanctuary team, an organization who track down several abnormals around the world and give them refuge at one of their bases, and become her new protégé.

[8] In an alternate future in the season two episode "Pavor Nocturnus", which takes place ten years into the episode's future where the world is overrun by zombie-like creatures after Magnus unknowingly unleashed a virus while curing her longevity, Will is depicted as the only living survivor of the Sanctuary Network.

[9] While on assignment in Mumbai, in "Kali", Will becomes host to a Macri, a creature with a connection to Big Bertha, the most powerful abnormal on Earth.

However, Terrance Wexford (Paul McGillion) takes command of the Sanctuary Network, and attacks Bertha, causing her to turn on Will and create three tsunamis.

[16][17] In "Metamorphosis", it is revealed that on his travels to Hollow Earth, he became infected from a reptilian creature called a Cillobar, and is slowly transforming into one.

He gradually loses his inhibitions, and escapes the Sanctuary until he is captured again when Magnus finds a cure to his condition, where he would transform back to human.

[18] In the season finale "Into the Black", Will overlooks the exodus of several abnormals from Hollow Earth, where it is revealed Praxis is destroyed, having been caused by Magnus' nemesis Adam Worth (Ian Tracey), who attempts to travel back in time to save his dead daughter.

I find that a really good character trait.Will Zimmerman is described by Syfy as "a brilliant forensic psychiatrist" and a "master of behavioral science" who "can translate the most veiled human signals into case-breaking deductions.

[20] Will Zimmerman came from an idea of a young psychiatrist "co-op[ing]" with the lead character to "track down monsters and help people" when Damian Kindler conceived Sanctuary in 2001.

[25] After the series was green-lit, director Martin Wood approached Robin Dunne, who he worked with a few years before, to appear on the show.

Dunne was initially reluctant to appear on what would start as a web series; the medium did not receive enough media attention when he was approached.

The television series also introduced "Will vision," a cinematic technique that shows Will's perspective on crime scenes (in frames, certain objects stand out).

[20] Critical reactions behind the character and Dunne's portrayal were generally positive, with some reviewers commenting that Zimmerman is somewhat of Sanctuary's equivalent of Daniel Jackson from Stargate SG-1.

Instantly likable, able to seem intellectually gifted without being off-putting [...] Dunne's performance as Will is one of the more effortless realizations of the viewer-identification character in recent sci-fi/fantasy that I've seen.

[35] In 2010, Dunne won a Leo Award for "Best Lead Performance by a Male in a Dramatic Series" for the season two episode "Pavor Nocturnus".

[37][38] In 2011, Dunne was again nominated for a Leo Award for the episode "Vigilante",[39] but lost out to Shattered actor Callum Keith Rennie.