Webb joins the ICSS, which is based in Qatar, having played a key role in attempting to establish the legacy for London 2012.
She was executive director for marketing and comms at the Olympic Park Legacy Company for two years before going on to launch her own consultancy last January.
Webb steps in for Heinz Palme, who was filling the ICSS position on an interim basis and will now continue his role as ICSS director of business development.
She will build upon the ICSS’s ongoing activities, including the Save The Dream initiative and events such as Securing Sport 2014.
Webb will also advise on the further development of the ICSS’s sports governing body and stakeholder engagement strategy.
Mohammed Hanzab, President of ICSS, praised her "wealth of experience" and track record of work with "international players in the business of sport" over her 25 year career.
This also includes holding senior roles with the Sydney 2000 Organising Committee and the International Olympic Committee.
Hanzab added: "With security and integrity stories currently dominating the news agenda, I look forward to working with Karen to develop the next chapter of the ICSS story."
Through her own business, Webb advised a number of international sports federations, UK Legacy charity, Sported, and companies including BT and Westfield.
She also advised UK Sport and the Mayor of London’s Office on major events, international business engagement and legacy planning around the Games.
The ICSS is an international, not-for-profit institution that aims to help event organisers to stage safer major sporting events.