Siobhan O’Brien leads the Cyber Centre of Excellence for MSIG globally, shaping strategy and underwriting direction globally for the organization. She joined MSIG USA in January 2025 to establish the company’s cyber platform, bringing deep expertise from an extensive career in insurance and reinsurance broking in both the UK and the US. Prior to MSIG, she most recently led the Cyber Centre of Excellence at Guy Carpenter.

In April 2025, Siobhan announced the launch of MSIG USA’s cyber underwriting team, responding to the rapid growth of cyber insurance in the market and the increasing need for businesses to secure tailored protection against evolving digital threats. She later introduced a strategic partnership with Coalition to serve multinational businesses operating in the U.S., combining MSIG USA’s financial strength and global reach with Coalition’s advanced cyber risk technology.

 Her mandate extends beyond building MSIG USA’s cyber portfolio to anticipating emerging trends, influencing market direction, and driving innovation in one of the industry’s most dynamic sectors. Recognized as a thought leader, she has spoken at leading industry events in London and internationally and is a published author on a range of cyber insurance topics.