Lord Dyson, Master of the Rolls, said: "The claimants say that their exclusion from the franchise is an unjustified restriction on their EU right - EU law right - of free movement and contrary to their constitutional, common law right to vote.
"For the reasons set out in the judgments that are handed down, the appeal against the dismissal of their claims is dismissed. The court holds first that the EU Referendum Act 2015 does not fall within the scope of EU law at all, so that the claim fails at the first hurdle."
He added that "the common law right to vote does not take precedence over an Act of Parliament" and refused permission to appeal to the Supreme Court.
However, lawyers for the expats said they would still be taking the case to the Supreme Court on Tuesday, 24 May 2016, and that permission to appeal - as well as the merits of the appeal itself - would be considered at the hearing.
Two Britons living abroad have lost their Court of Appeal battle over the right to vote in June's EU referendum.The legal challenge was brought by World War Two veteran Harry Shindler, 95, who lives in Italy, and lawyer and Belgian resident Jacquelyn MacLennan. Under law, UK citizens who have lived abroad for more than 15 years cannot vote. The pair took the case to the Court of Appeal after losing their application for a judicial review last month. They asked High Court judges to declare that s.2 of the EU Referendum Act 2015, which established "the 15-year rule", unlawfully restricted their right to freedom of movement under EU law. The judges ruled that the section did not restrict their rights and rejected their application for judicial review.