Carl Benjamin, who posts online using the moniker Sargon of Akkad, is one of two candidates the Eurosceptic party named on Thursday to stand in the southwest region.
“We went through an exhaustive process to sift over 190 potential candidates down to those the national executive committee representatives and I felt were most suitable,” Ukip leader, Gerard Batten said.
“This list is based on a number of factors that we felt would select candidates to fight for a real Brexit after the European elections. Ukip’s priority is to have MEPs who will fight to make Brexit happen.”
Mr Benjamin has close to one million subscribers to his YouTube channel, on which he produces videos criticising feminism, left-wing politics and the European Union.
He gained mainstream attention after being accused of promoting a series of rape threats from Twitter users against Labour MP Jess Phillips in 2016.
Ms Phillips had written: “People talking about raping me isn’t fun, but has become somewhat par for the course” on the social media site, leading Mr Benjamin to reply: “I wouldn’t even rape you, Jess Phillips.”
His followers went on to repeat his statement and Ms Phillips later tweeted: “600-odd notifications talking about my rape in one night. I think Twitter is dead.”
A Ukip spokesman has previously condemned Mr Benjamin’s comments, telling The Independent at the time he joined the party the exchange with Ms Phillips was “unpleasant”.
Mr Benjamin is one of several prominent social media activists to join the party under the leadership of Mr Batten, who has been accused of pulling the party towards the hard right.
Paul Joseph Watson, the editor-at-large of Alex Jones’ far-right InfoWars website and a YouTuber with more than 1.6 million subscribers, also joined the party in 2018.
Mr Batten has also come under fire for appointing anti-Islam activist Tommy Robinson in an advisory role, a move that caused long-time Ukip leader Nigel Farage to quit the party.
The UK is likely to take part in European elections in May after EU leaders agreed to grant a flexible six-month extension to the Article 50 process on Wednesday.