Trump's announcement comes three days before the Republican National Convention opens in Cleveland, Ohio, where Trump will officially become the party's presidential nominee. That was Pence on Twitter in December after Trump proposed a "total and complete shutdown" of Muslims entering the U.S.
Pence represents a relatively safe pick for Trump, and brings years of legislative and executive experience.
About 24 hours after multiple media outlets reported that Indiana Gov. Mike Pence would be Donald Trump's pick for the vice presidential slot on the Republican ticket and Trump's camp then denied that any decision had been made, the candidate himself made it official on Friday. Pence would be a reliably conservative No. 2 with a calm demeanor and deep ties to Washington.
"Pence also personally led the fight to defund Planned Parenthood while serving in the House and fought to pass Indiana's 2016 anti-abortion law, with some of the most outrageous restrictions in the country that threatened women's privacy and limited their choice". "He is choosing a person who has the experience inside and outside Washington, Christian conservative, very different style that I think shows a lot of maturity".
Pence also speaks frequently of his Christian faith and may allow Trump to make inroads with evangelical voters.
"You know, you shut the door, you tell the boss exactly what you think", Pence said on Fox News when asked by host Sean Hannity how he'd work through disagreements with Trump.
The Indiana governor also suggested he would loosen up on his past backing of USA trade deals, particularly the Trans-Pacific Partnership and the North American Free Trade Agreement. Ted Cruz instead of Trump ahead of Indiana's presidential primary.
Other candidates in the running to stand with Mr Trump were the former speaker of the House, Newt Gingrich and the New Jersey Governor, Chris Christie.
'By picking Mike Pence as his running mate, Donald Trump has doubled down on some of his most disturbing beliefs by choosing an incredibly divisive and unpopular running mate known for supporting discriminatory politics and failed economic policies that favour millionaires and corporations over working families, ' said Clinton campaign Chairman John Podesta. With Pence sitting in a NY hotel, Trump made a decision to postpone the announcement.
Trump held a midnight conference call with his top aides to discuss the situation, according to two people with knowledge of the call.
Over the last week in the run-up to Trump's Friday tweet announcing his pick, Pence had dodged answering reporters' questions in IN over his conflicting stances, including whether he endorsed Trump's proposal to build a wall on the U.S.-Mexico border.