The BBC is facing a $US10 billion ($A14 billion) lawsuit from Trump, who accuses the publicly funded United Kingdom broadcaster of defamation over how it spliced together footage of parts of a speech he gave on January 6, 2021, before some of his supporters stormed the US Capitol.
The broadcaster has argued the lawsuit should be dismissed, saying Trump's subsequent re-election showed the alleged defamation did not harm his reputation.
Brittin joined Google in 2007 as head of UK and Ireland before rising through the ranks to become Europe, the Middle East and Africa president in 2014.
He stepped down in 2024 and will take on the new role from May 18.
Brittin said the 104-year-old BBC is "an extraordinary, uniquely British asset".
"This is a moment of real risk, yet also real opportunity. The BBC needs the pace and energy to be both where stories are, and where audiences are," he said in a statement.
"To build on the reach, trust and creative strengths today, confront challenges with courage, and thrive as a public service fit for the future. I can't wait to start this work," he added.
Reflecting his lack of editorial or broadcast experience, the BBC said he would appoint a deputy director general.
Brittin, 57, steps in at a critical moment.
He will have to negotiate a new funding settlement after the broadcaster's royal charter expires at the end of 2027.
Options include retaining the licence fee paid by TV watching households or moving to subscriptions or ad-funding.
The BBC is facing a battle to stay relevant as viewers, particularly younger audiences, shift to streamers and other digital platforms.
The job also comes with intense political scrutiny, with the BBC subject to criticism from across the spectrum about its impartiality, putting pressure on an institution long regarded as one of the UK's most trusted and enduring cultural fixtures.
A documentary aired days before the 2024 US presidential election spliced together three quotes from a speech into what appeared to be one quote in which Trump urged supporters to march with him and "fight like hell".
Trump is suing the broadcaster for defamation in a Florida court.
with Reuters
