Jonathan has served as Senior Partner of Thornhill since 2021, having previously led the firm's M&A practice for a decade. He joined Thornhill as a trainee in 1999 and was made partner in 2009, going on to advise boards, sponsors and financial advisers on transactions across the industrials, financial services and consumer sectors. He continues to advise on a select number of the firm's most significant public and private transactions, including the board of a listed industrials group on a recommended public takeover, a listed financial services group on its acquisition of a regional competitor, and a listed consumer goods company on its response to an unsolicited approach, alongside a cross-border public company merger effected by way of scheme of arrangement.

Alongside his transactional practice, Jonathan is regularly instructed on matters requiring close coordination between corporate, regulatory and disputes specialists, reflecting the firm's approach of assembling teams around a client's needs rather than along strict departmental lines. Since becoming Senior Partner, he has overseen the firm's expansion into New York and Hong Kong, and sits on the International Board, which sets the firm's strategy across its three offices.

Jonathan holds an LL.B. from the University of Bristol and was admitted in England and Wales in 2001. He is a member of the Law Society of England and Wales and the City of London Law Society's Company Law Committee.