Leslie Kosmin KC is Visiting Professor in Practice at LSE Law School. He is also an Affiliated Lecturer at the University of Cambridge where he teaches a course on Shareholder Litigation for the Cambridge MCL programme.

He was a senior counsel at the Chancery Bar until he retired from practice in 2011. After taking degrees at Cambridge and at Harvard Law School in the 1970s (for which he was awarded a John F. Kennedy Scholarship) he joined Erskine Chambers, the UK's leading Company Law set, in 1977. He took silk in 1994 and was appointed a Deputy High Court Judge of the Chancery Division of the English High Court in 2001.

During his time at the Bar he specialised in Company Law and Corporate Insolvency, and had a wide advisory and extensive litigation practice. He was instructed in relation to legal proceedings throughout the UK as well as in Hong Kong and a number of Commonwealth jurisdictions including Bermuda, the British Virgin Islands, the Cayman Islands, Guernsey, India, Jersey, Malaysia, Singapore and the Turks and Caicos Islands.

He is the joint author (with Catherine Roberts) of "Company Meetings and Resolutions: Law, Practice and Procedure" (2nd edition Feb 2013 OUP), advisory editor in relation to "Directors Duties" by Prof Andrew Keay (pub. Jordans 2009) and a contributor to "Practice and Procedure of the Companies Court" (1997).