A White House official said Spicer, 45, had resigned.
Spicer's departure reflected turmoil within Trump's legal and communication teams amid a widening investigation into possible ties between Trump's 2016 presidential campaign and Russia, a problem undermining the White House's policy agenda.
Parodied memorably on the Saturday Night Live sketch comedy show for his combative encounters with the White House press corps, Spicer became one of the Trump administration's most recognized figures after taking the job in December.
He was sometimes targeted by critics for what they said were false or misleading statements. In recent weeks, Spicer has less frequently taken the lectern in the White House press room.
Trump offered Scaramucci, a longtime supporter who has frequently appeared on television to defend him, the White House communications post.
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