Construction of the 4m-high concrete structure along the main motorway to the port in northern France finished on Friday, a spokesman from the Calais prefecture said.
It comes around six weeks after the refugee and migrant camp known as The Jungle was demolished, with thousands of its residents taken by bus to temporary accommodation centres across France.
The barrier, intended to add a further layer of protection against attempts to delay or attack vehicles as they approach the port, took around 12 weeks to complete.
The project came under the spotlight in early September when Immigration Minister Robert Goodwill announced security at the port would be stepped up with “better equipment”.
He told MPs: “We are going to start building this big new wall very soon. We’ve done the fence, now we are doing a wall.”
The UK has committed around £85 million to reinforce security in the Calais region. French officials estimate the wall has cost 2.7 million euros (£2.3 million).