The announcement was made moments ago at the start of Wednesday's "Today" show by co-anchor Savannah Guthrie.
Guthrie said she was “heartbroken for the brave colleague who came forward to tell her story" while calling Lauer a "dear, dear friend."
She said she had heard about the firing just moments before coming on air.
“How do you reconcile your love for someone with the revelation that they have behaved badly?” Guthrie said.
NBC said it received a detailed complaint on Monday from a staffer about inappropriate sexual conduct in the workplace by Lauer that was "a clear violation of our company's standards."
While it was the first complaint the network said it received in Lauer's 20-plus years at NBC, NBC News Chairman Andrew Lack said, "We were also presented with information that this may not . have been an isolated incident."
Lauer is a Hartsdale native who also lived in North Salem. After transferring from Woodlands High School in Westchester, Lauer graduated from Greenwich High School in Fairfield County and Ohio University. He lives in Manhattan with his wife of 19 years, two sons and a daughter.
Lauer became co-anchor on "Today" in January of 997. He joined "Today" three years earlier as the show’s news anchor. From September 1992 to September 1996, Lauer was at WNBC-TV where he served as a co-anchor of the early morning newscast “Today in New York” and as a co-anchor of the early evening newscast “News Channel 4/Live at Five.”
Prior to that, he hosted a daily, live, three-hour interview program, “9 Broadcast Plaza,” in New York from 1989 to 1991 on WWOR-TV.
The 59-year-old Lauer, considered the most powerful figure at NBC News, had signed a two-year contract renewal for $20 million per year in November 2016.
On Twitter, President Donald Trump said "Wow, Matt Lauer was just fired from NBC for 'inappropriate sexual behavior in the workplace.' But when will the top executives at NBC & Comcast be fired for putting out so much Fake News."
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