What is the name of Mulder's confidential informant in season one?

What is the name of Mulder's confidential informant in season one? The answer is Deep Throat.

Deep Throat was Fox Mulder's first major confidential informant on The X-Files. He secretly supplied information about paranormal investigations and government activity, often meeting Mulder in isolated public places and speaking in deliberately cryptic terms. The character was played by Jerry Hardin.

Introduced in the second episode, also titled “Deep Throat,” the informant was connected to the mysterious Syndicate and knew more about its secrets than Mulder could discover through official channels. He believed that Mulder was capable of exposing hidden truths, although he sometimes misled him because he thought the public was not ready for certain revelations.

A common mix-up is identifying The Lone Gunmen or Mr. X as the season-one informant. The Lone Gunmen are recurring conspiracy theorists, while Mr. X becomes an important source later. Deep Throat was killed in the first-season finale, “The Erlenmeyer Flask,” but later appeared in visions and flashbacks.