Sir Nicholas Edward Underhill (born 12 May 1952), styled The Rt Hon. Lord Justice Underhill, is a British judge of the Court of Appeal of England and Wales.

He was educated at Winchester College and New College, Oxford.^[1]

Underhill was called to the bar at Gray's Inn 1976 (elected a bencher 2000). He became a Queen's Counsel in 1992. He was appointed a Recorder in 1994 and was authorised as a deputy High Court judge in 1998. From 2000 to 2003, he was a temporary additional judge of the Employment Appeal Tribunal. He served as Attorney-General to the Prince of Wales from 1998 to 2006.^[2] On 30 January 2006, Underhill was appointed a High Court judge,^[3] receiving the customary knighthood, and assigned to the Queen's Bench Division. He was a judge of the Employment Appeal Tribunal from 2006 to 2013, and its president from 2009 to 2011.^[4] On 9 April 2013, he was appointed a Lord Justice of Appeal^[5] and consequently appointed to the Privy Council.

Underhill was chair of the Bar Pro Bono Unit (2002–2005). He has served as a trustee of St John's, Smith Square since 1996 and as chair since 2010. He is also a trustee of the London Library, having served since 2008, and has been vice chair since 2011.^[2]

He received an Honorary Fellowship from New College, Oxford in 2015.^[6]

• Wilson v United Kingdom [2002] ECHR 552, acting for the Daily Mail. Lost.
• Byrne Bros (Formwork) Ltd v Baird [2002] ICR 667, subordination and dependence as the keys to employee status. Rejected by the Supreme Court in Clyde & Co LLP v Bates van Winkelhof [2014] UKSC 32, [39].
• R v Barnet London Borough Council ex parte Nash, 2013 ^[7]
• Reilly v Secretary of State for Work and Pensions [2016] EWCA Civ 413, saying the government breached the Human Rights Act, but suggesting the government needed to do nothing
• Pharmacists Defence Association Union v Secretary of State for Business, Innovation and Skills [2017] EWCA Civ 66, refusing recognition of a trade union, unless a sham union was first derecognised
• Uber BV v Aslam [2018] EWCA Civ 2748, dissenting to hold drivers were not workers. Rejected by the Supreme Court, [2021] UKSC 5.
• IWGB v Roofoods Ltd [2021] EWCA 952, holding Deliveroo cyclists did not have a human right to join trade unions
• Adedeji v University Hospitals Birmingham NHS Foundation Trust [2021] EWCA Civ 23, Underhill approving the refusal of a claim that was 3 days late under the Equality Act 2010.