Mr Benjamin had the milkshake thrown on him as he was campaigning for the European Elections.
While in Salisbury on Sunday afternoon, the 29-year-old was targeted in the street after already having milkshakes thrown on him at previous rallies.
An image of Mr Benjamin covered in the milkshake was posted on Twitter by a witness who wrote: “Welcome to Salisbury”.
Dear Racist vile human welcome to Salisbury pic.twitter.com/M1DGjgzWc1— Nigel (@Stegsythedog)May 19, 2019
Far-right figure Tommy Robinson and Mr Benjamin have had food and drinks thrown at them on multiple occasions during their European election campaign.
Former English Defence League leader Mr Robinson was drenched by milkshakes twice in two days as he campaigned in the north west of England.
The targeted drink throwing caused police in Scotland to warn McDonald’s not to sell milkshakes or ice creams over fears someone would throw product at Nigel Farage as he delivered a speech in Edinburgh.
The fast food restaurant said it received a request from police not to sell the products while the Brexit Party leader spoke at a rally because of “recent events”.
Carl Benjamin, UKIP's candidate for South West England, is under police investigation for comments he made on Twitter about raping the Labour MP Jess Phillips.