Henry Bolton has already stressed he will seek to unite Ukip after defeating a candidate whose description of Islam as "evil" had threatened to split the party.
The new leader of the UK Independence Party (UKIP) will be announced on Friday amid fears the fractured movement could collapse entirely.
But he comfortably saw off the challenge of anti-Islam campaigner Anne Marie Waters, who came second with 21.3 per cent of the 12,915 votes cast.
Despite being relatively unknown, the ex-Thames Valley police officer, who joined the party in 2014, is no stranger to running for elected posts.
Bolton won 3,874 votes, ahead of 2,755 for Waters. He stood for the Liberal Democrats in the 2005 general election and spent time working as a common defence strategist for the European Union.
Other contenders in the race were anti-Islam candidate Anne Marie Waters; the party's deputy leader Peter Whittle; London Assembly member David Kurten; MEP Jane Collins; Aidan Powlesland, and John Rees-Evans.
Ending his speech, he said: "Whilst brexit is our core task, that greater goal which is ongoing beyond the time that we leave the European Union - that is our core objective".
"We want the right to self-determination", Bolton said, calling for an end to decisions affecting Britain being made in a foreign capital. BBC political correspondent Ben Wright said Mr Bolton would be seen as the continuity candidate. Bolton reportedly said he was "fine" with the new design. I do not see myself as being your leader, I see myself as serving this party.
The favourite to replace her, Steven Woolfe, pulled out following an altercation with a fellow MEP at the European Parliament that left him hospitalised.
The protesters stood with banners reading: "We say no to racism". She resigned after just 18 days in the post, saying she could not work with the party hierarchy.