The 43rd president -- who had his own battles with the press while in office -- rejected Trump's assertion that the media are the "enemy of the American people."
"I consider the media to be indispensable to democracy. That we need the media to hold people like me to account," Bush told NBC's "Today" program.
Trump's inflammatory remarks have been criticized as authoritarian, but the media remains a popular whipping boy for his supporters.
Amid wave after wave of leaks from his White House and probing reports on his campaign's links with Russia, Trump has repeatedly decried the media as "fake news."
Influential Trump aide Steve Bannon is fond of referring to the media as the "opposition party."
Bush responded to that sentiment by saying "power can be very addictive and it can be corrosive, and it's important for the media to call to account people who abuse their power."
Bush also described Trump's comments as undercutting America's efforts to promote democracy and the free press abroad.
Bush wants 'answers' over Russia relations
Bush says "we all need answers" on the extent of contact between President Donald Trump's team and the Russian government, and he defended the media's role in keeping world leaders in check.
Bush said he would trust Senate Intelligence panel Chairman Richard Burr to decide if a special prosecutor is necessary.
But, Bush said: "I think we all need answers ... I'm not sure the right avenue to take. I am sure, though, that that question needs to be answered."
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