Leo Thomas McGarry is a fictional character

Fictional character

A character is the representation of a person in a narrative work of art . Derived from the ancient Greek word kharaktêr , the earliest use in English, in this sense, dates from the Restoration, although it became widely used after its appearance in Tom Jones in 1749. From this, the sense of...

 played by John Spencer

John Spencer (actor)

John Spencer was an American film and television actor. He was most widely known for playing White House Chief of Staff Leo McGarry on the NBC political drama series The West Wing, which earned him an Emmy Award in 2002.-Early life:Spencer was born as John Speshock, Jr. in New York City, and...

 on the television serial drama The West Wing

The West Wing (TV series)

The West Wing is an American television serial drama created by Aaron Sorkin that was originally broadcast on NBC from September 22, 1999 to May 14, 2006...

. The role earned Spencer the 2002 Emmy for Outstanding Supporting Actor in a Drama Series. McGarry's character, the former United States Secretary of Labor

United States Secretary of Labor

The United States Secretary of Labor is the head of the Department of Labor who exercises control over the department and enforces and suggests laws involving unions, the workplace, and all other issues involving any form of business-person controversies....

, begins the series as the White House Chief of Staff

White House Chief of Staff

The White House Chief of Staff is the highest ranking member of the Executive Office of the President of the United States and a senior aide to the President.The current White House Chief of Staff is Bill Daley.-History:...

. He is President Josiah Bartlet

Josiah Bartlet

Josiah Edward "Jed" Bartlet is a fictional character played by Martin Sheen on the television serial drama The West Wing. He is President of the United States for the entire series until the last episode, when his successor is inaugurated...

's best friend and a father figure to the Senior Staff, particularly Deputy Chief of Staff Josh Lyman

Josh Lyman

Joshua "Josh" Lyman is a fictional character played by Bradley Whitford on the television drama The West Wing. For the majority of the series, he was White House Deputy Chief of Staff in the Josiah Bartlet administration...

.
In crafting the character of Leo McGarry, series creator Aaron Sorkin

Aaron Sorkin

Aaron Benjamin Sorkin is an Academy and Emmy award winning American screenwriter, producer, and playwright, whose works include A Few Good Men, The American President, The West Wing, Sports Night, Studio 60 on the Sunset Strip, The Social Network, and Moneyball.After graduating from Syracuse...

 says he envisioned John Spencer in the part but had not imagined he would be available.