Tobias "Toby" Zachary Ziegler is a fictional character in the television serial drama The West Wing, played by Richard Schiff. The role of Toby Ziegler earned actor Richard Schiff the Primetime Emmy Award for Outstanding Supporting Actor in a Drama Series in 2000. For most of the series' duration, he was White House Communications Director. In the final season, Ziegler was involved in a storyline around a leak of classified information, which The New York Times compared to the leak investigation of the Valerie Plame affair.

According to series creator Aaron Sorkin, Schiff was cast in the role of Toby Ziegler over many other actors who auditioned, including Eugene Levy. Schiff created a backstory for the character as a widower and wore his own wedding ring. Sorkin and fellow executive producer Thomas Schlamme were planning for the character to be divorced, and did not notice until the show's eighth episode. "I had always imagined that his first wife had died, which accounts for his sadness, and why someone would devote himself to public service and be so singular about it", Schiff said. "But then, Aaron and Tommy threw that right out the window."

Schiff had publicly praised the show's writers, and creator Aaron Sorkin in particular, for the characters' richness in the series. However, during the show's final season, Schiff said he felt let down by the writers as some of his episodes were cut "purely on a financial decision." He was particularly critical of the military shuttle leak storyline, which saw his character indicted for leaking classified information. "Toby would never in 10 million years have betrayed the president in that fashion," Schiff said. "Even if he had, there would have been seven episodes' worth of fights before he did it." He justified the story to himself by reasoning that Toby was covering for somebody else.

The character is Jewish and grew up in the New York City borough of Brooklyn with an immigrant father who was a convicted member of Murder, Inc., the Jewish mafia's enforcement arm, a background in part inspired by Richard Schiff's own family history. Before joining the Bartlet presidential campaign, Toby was a professional political operative who worked for various campaigns, including New York City Council seats, Bronx Borough President and U.S. House and Senate races. It is implied in the episode "And It's Surely to Their Credit" (by the statement "everyone in the room is a lawyer") that Toby has a law degree.

Toby is rather morose, yet he is something of an idealist, often less willing than his colleagues and the president to compromise his political values. He is shown to be a more than formidable opponent in an argument, easily able to hold his own against even Bartlet himself. He is also known for his acerbic wit.^{[citation needed]}

In season 1 of The West Wing, Toby Ziegler was Communications Director and senior domestic policy advisor to President Bartlet. Season 1 began in their first year in office, detailing the teams' efforts to pass legislation despite unfavorable political circumstances and a powerless administration in the face of the opposition. Toby works with his ex-wife Andrea "Andy" Wyatt, a member of the House of Representatives, on criminal justice legislation. The season ends on a cliffhanger with an assassination attempt but no information on who has been hit.

Season 2 of The West Wing details President Bartlet's second and third years in office. The season begins with the assassination attempt from the last episode of the prior season. After the attack, Toby is in a morose mood and eager to punish hate groups he sees as responsible for the assassination attempt. It is revealed once in the White House, Toby was rewarded for his work on the campaign, with Bartlet naming him Communications Director and senior domestic policy advisor. In episode 18, Toby argues with the President after finding out about the latter's multiple sclerosis diagnosis. Later in the season, he reveals the news to less senior members of the team.

The third season covers the second half of Bartlet's first term and begins with the news that he was seeking re-election. It is revealed that Toby's mother has been dead for 12 years. Both he and his father mention sisters, who Toby said took him to protest rallies in the mid-1960s, as well as nieces and nephews. His younger brother, David, is a mission specialist at NASA who dies by suicide after learning that he has terminal cancer. Toby also refers to a grandfather who lived to be 96 years old, but for the last 20 years of his life, "thought the Habsburgs still lived in a big palace in Vienna."