Farage, one of Britain's leading Brexit campaigners, in a highly unusual move did not turn up at count in the southern English seaside resort of Clacton because he said the police had advised him that there was a campaign to disrupt the result.
He also cancelled a victory speech planned for later on Friday.
"I am damned if I am going to stand on a stage, having won a resounding victory ... and be demeaned and humiliated by nobodies," Farage told supporters at a party before the result was announced on Friday.
He claimed he had won "fairly convincingly" and the result was an "overwhelming endorsement" of him.
The election was triggered after Farage resigned from parliament in July to seek a fresh mandate from voters in what he described as a war against an establishment bent on discrediting him over taking undeclared gifts from donors.
After Britain's main parties pulled out of the race, calling it a self-serving stunt, Farage's main challenger ended up being Count Binface, a figure created by comedian Jonathan Harvey, who has become a fixture of fun at British elections.
While Farage took 62.8 per cent of the vote, Count Binface, whose policies included capping the price of ice-cream cones and conscripting anyone using a speakerphone on public transport, secured second place with 26.7 per cent.
The turnout was 44 per cent.
After enjoying a lengthy lead in the opinion polls, Reform has seen its popularity wane, driven partly by the funding accusations made against Farage, who is under investigation in parliament over whether he should have declared a Stg5 million ($A9.5 million) gift from a cryptocurrency billionaire investor.
After declaring his decision to trigger the election in Clacton little more than a ploy to distract from those allegations, other British parties pulled out of the race, leaving even some of Farage's strongest supporters questioning whether the veteran politician had been wrong-footed.
Farage's position has not been helped by a rise in support for the governing Labour Party.
Since Andy Burnham became prime minister in July, Labour has enjoyed a bounce in ratings, with the party leading Reform 28 per cent to 25 per cent.
Reform, on the other hand, is competing for a divided right-wing vote with the Conservative Party and the anti-immigration party Restore Britain gaining in support.
Despite winning this vote, the parliamentary watchdog is expected to continue its investigation into his financial declarations once he returns to parliament.
At the heart of the investigation is whether he should have declared the gift from a Thailand-based billionaire before the 2024 national election.
Under parliamentary rules, MPs must declare any donations received in the year preceding an election within one month of taking office.
Farage has admitted receiving the money, but not declaring it, saying he has done nothing wrong because it was a personal gift.
If the parliamentary authorities conclude that Farage breached declaration rules, he could face a suspension from parliament, and another vote to retain his seat, where the main parties would probably field candidates.
Speaking to Sky News, Count Binface referred to the possibility of a second by-election.
"You just said at the beginning of this interview that Nigel Farage is claiming victory, but in that case it's going to be a two-legged match like the Carabao Cup or the Cold War, because we're going to be back again in a few weeks, aren't we? We'll see what happens then," he said.
"Even if I got to 12 per cent, so one-in-eight people in Clacton would rather vote for a space warrior shaped like a bin than Nigel Farage."
with PA
