Daniel Joseph Brennan, Baron Brennan, KCSG, QC (born 19 March 1942) is a British Labour life peer and barrister.
Brennan was educated at St. Bede's Grammar School, Bradford, and graduated with a Bachelor of Law degree from Manchester University, where subsequently he was awarded an honorary Doctorate in 2000.
A member of Matrix Chambers specialising in personal injury and medical work, commercial law, international business issues, public and private international law, and international arbitration, he was called to the bar at Gray's Inn in 1967. He became a Queen's Counsel in 1985, and he is a Deputy High Court Judge and a Recorder in the Crown Court, a former member of the Criminal Injuries Compensation Board and ex-Chairman of the Personal Injuries Bar Association.
Lord Brennan is the Bar representative on the Council of the International Bar Association. He is also a member of the bars of the Republic of Ireland and Northern Ireland. In 2000, The Lawyer Magazine described him as Barrister of the Year.
Lord Brennan is Chair of the APPG on Legal and Constitutional Affairs, which is a cross party grouping of MPs and Peers with Parliament focussed on discussing issues relating to the legal profession and the reform of the law and constitution.