Brendan Patrick Donnelly (born 25 August 1950, London) is a pro-European Union British politician.
Donnelly was elected as a Member of the European Parliament in Sussex South and Crawley at the European Parliament election, 1994 for the Conservative Party. He then left the party, continued as an independent for a period, and then co-founded and became deputy leader of the Pro-Euro Conservative Party at the 1999 European elections.
He failed to get elected and subsequently joined the Tunbridge Wells Liberal Democrats. He stood in the 2009 European elections under the Yes2Europe political label. He stood in the 2014 European elections for the 4 Freedoms Party (UK EPP).
Donnelly is director of the Federal Trust and, until 6 March 2010, was chair of Federal Union, when he was succeeded by Richard Laming.