TCS opened offices in New York and Los Angeles on 4 October.
Attias, who joins from global executive search firm Grace Blue, where she was a partner, has been hired to help build TCS's international offer and grow the consumer practice. She is based in London.
In 2010, Attias set up the UK office of French PR agency ELAN (which has since been acquired by Edelman) and has also worked for TBWA and MSLGroup in Paris.
TCS founder and CEO Julietta Dexter said: "We are delighted that Jennifer has joined us during an interesting growth phase as we expand our client services so we can properly look after our clients in the US market too, with offices in LA and NY.
"Mark, Craig and Jennifer are strengthening our creative, operational and client servicing skills as we evolve our business management and client service teams. These key hires are vital stepping stones to developing and growing our business."
TCS's clients are primarily in the fashion and beauty sectors, including Burberry, Jimmy Choo, Top Shop and Ralph Lauren.
It also has clients in the restaurant and drinks industries, working with high-profile chef Simon Rogan and drinks brands Dom Perignon and Veuve Clicquot. Earlier this month PRWeek reported that TCS had won the brief to represent chef Gordon Ramsay’s UK restaurant business.
