The former British Army officer was voted in as leader at the Ukip party conference in Torquay this afternoon.
He secured a shock victory over front-runners Ann-Marie Waters and London Assembly member Peter Whittle.
Mr Farage helped Mr Bolton to victory with a key endorsement – securing the former Ukip leader with a replacement he approved of.
In the immediate aftermath of the result, Mr Farage said he was “delighted”.
He said: “I am delighted Henry Bolton has won the Ukip leadership election.
“He is a man of real substance.”
Mr Bolton warned earlier this month Ukip was in danger of becoming the “UK Nazi Party” if it picked the wrong leader to succeed Paul Nuttall. These comments appeared to be aimed at Ms Waters, an anti-Islam campaigner.
Speaking after being announced as new leader, he called on Ukip to rally around and support their campaign to secure a hard Brexit.
He said: “I do not see myself now as simply being your leader, I see myself as serving this party.
“You are the party, not me, and this party needs to serve its country.
“There is no greater calling than that and I would call on all of you, whether you voted for me or not, to rally around the party, to be united.”
Mr Bolton told audience members at the conference he would hold the UK government “to task” – especially over Brexit.
He said: “Brexit is our core task, however, it is not the end of the line.
“Brexit does not end the day we leave the European Union. We have to take control of our destiny.”
Some 12,915 votes were cast in the leadership election, a 46% turnout.
Mr Whittle, who had been touted as a likely winner, came a surprise fifth with 1,413 while Ms Waters came second with 2,755 votes, a 21% vote share.
Up to 18 of the 20 Ukip MEPs had been reportedly preparing to quit the party if Ms Waters had won the leadership battle.
Mr Bolton secured 3,874 votes.
Mr Bolton was previously a Lib Dem member and ran as a candidate in the 2005 election.
He finished third in Runnymede and Weybridge with 17.9 per cent of the vote.
Labour finished second with 23 per cent and Philip Hammond stormed to a Tory victory with 51.4 per cent.