William Willson > South Square > London, England > Barrister Profile

South Square


William specialises in insolvency and restructuring, banking and finance and commercial litigation. His busy practice also includes civil fraud, company law, financial services, professional negligence, shipping, insurance and real property. Many of his cases have an international element, and he is particularly interested/experienced in cases involving Russia/the CIS. In the last 12 months he has been instructed in relation to many of the major insolvencies/restructurings, including Virgin, Debenhams, Arcadia, British Steel and Lehman Brothers.

In recent years William has appeared successfully in several high-profile trials, both at home and abroad, including the ongoing dispute about the ranking/priority of $10 billion of Lehman Brothers’ subordinated debt, and the $2 billion professional negligence claim by Primeo (a Madoff ‘feeder fund’) against HSBC. In the next 12 months he is instructed to appear in the Privy Council and the Court of Appeal, as well as trials in both the Commercial Court and the Chancery Division.

William has appeared as sole Counsel in the Court of Appeal, the Court of Appeal of the Cayman Islands and the Court of Appeal of the Eastern Caribbean Supreme Court. He has been called to the Bar of Gibraltar (2013), the Cayman Islands (2014) and the British Virgin Islands (2016).

Before practicing at the Bar, William was a journalist/documentary producer, specialising in the former Soviet Union, terrorism and the intelligence services. His credits include the triple-BAFTA winning The Government Inspector.


Called 2006: called to the Bar of Gibraltar 2013: called to the Bar of the Cayman Islands 2014.


Chancery Bar Association, Commercial Bar Association, Insolvency Lawyers’ Association, INSOL International.


Oxford University (2000 MA Classics, First Class); City University (2005 CPE, Distinction); Inns Court School of Law (2006 BVC).

Lawyer Rankings

London Bar > Company

(Leading Juniors)Ranked: Tier 4

William WillsonSouth Square ‘William is a great operator – he has the confidence and skills of a KC, and a great commercial sense without compromising his pure legal knowledge.’

South Square is perhaps best known for insolvency and restructuring work in the corporate field, but members are frequently involved in high-value directors duties cases and other matters concerning the intricacies of company law, including having status of ‘the go-to set for offshore insolvency work’ with ‘a strong company practice, including incredible strength in depth’. David Alexander KC is currently acting for Incredible Power in a high-value shareholder litigation concerning claims of unfair prejudice, just and equitable winding-up, breach of fiduciary duty and conspiracy. David Allison KC’s strong company law practice saw him lead the counsel team for Nostrum Oil and Gas plc in a matter that raises novel issues concerning the impact of sanctions arising from the war in Ukraine. William Willson is a highly regarded senior-junior commercial Chancery practitioner.

London Bar > Commercial litigation

(Leading Juniors)Ranked: Tier 5

William Willson  – South Square ‘William is a go-to senior junior. He has seen everything and cuts through the chaff like few others can. William is a master client-handler, giving surefooted advice even under the most challenging of circumstances.’

London Bar > Insolvency

(Leading Juniors)Ranked: Tier 1

William WillsonSouth Square ‘William is a great operator – he has the confidence and skills of a KC, and a great commercial sense without compromising his pure legal knowledge. Clients are very comfortable with him advising unled and doing the advocacy at big hearings. He has a great connection with judges.’

‘The number one set for restructuring and insolvency matters,South Square has all of its members specialising within insolvency and restructuring law. Members, such as Mark Phillips KC have appeared in significant and high-profile insolvency cases in the UK, such as Sova Capital Ltd in which Phillips KC, alongside William Willson, put an investment broker focussing on the Russian markets into administration, which raised numerous complex issues from valuing claims to dealing with client claims, as well as how Moscow-listed assets would be handled by a UK company. ‘Extremely knowledgeable and unflappable‘ junior Charlotte Cooke  has appeared in a number of high-profile insolvency and restructuring cases, including three times in the Supreme Court, while Felicity Toube KC has depth in experience includes acting in major insolvency cases such as Greensill and Liberty Steel. David Allison KC has developed a strong cross-border practice, handling insolvency cases in the British Virgin Islands, Bermuda and Hong Kong, whereas Clara Johnson is noted for her experience in bringing and defending claims brought by officer holders involving fraud and where urgent injunctive relief is required.

London Bar > Banking and finance (including consumer credit)

(Leading Juniors)Ranked: Tier 2

William WillsonSouth Square ‘William’s strengths are his prodigious output and legal acumen. He is a master of detail and has an incredible memory. He knows a winning argument.’

London Bar > Fraud: civil

(Leading Juniors)Ranked: Tier 4

William WillsonSouth Square

The English Bar Offshore > The English Bar Offshore

(Leading Juniors)Ranked: Tier 1

William WillsonSouth Square