Mr Farage arrived in Nottingham to rally support for his East Midlands candidates for the European elections, but as he got out of a car in the city centre he was hit by the egg.
He quickly got back into the car which drove off leaving supporters behind.
The man who threw the egg was holding a placard which said: “Ukip . . . sad, scared, old men.”
The egg hit Mr Farage on the back of his head.
The protester, who gave his name as Fred from Nottingham, said he carried out the attack because he does not agree with Ukip policies.
He was put into a patrol car by police and driven away.
Mr Farage then went to the Bell Inn near the city’s town hall and ordered a pint of Robin Hood beer.
Police later confirmed a man from the city has been arrested on suspicion of assault.
Enjoying his pint of Robin Hood Ale, Mr Farage said he had been to the city before but this visit had been shorter than planned. He said: “I’ve been before [to the city] but today’s visit was a very brief one I’m afraid. I saw about 15 seconds of it. It’s quite tough to judge. Some of the inhabitants are not all that friendly. I’m sure that’s not the view of most.
“We’ve had a storm whipped up by the media over the injudicious, or in a couple of cases, offensive comments from a handful of people out of a membership of 37,000 and it’s whipped up this kind of storm of hatred among some on the left.
“They’re organised, they’re taxpayer funded and they’re going around the country chasing me around trying to stop us from getting our message out.
“That is a fundamentally anti-democratic thing to do.”