Rob Rosiello

Executive Partner at Flagship Pioneering

Rob Rosiello is executive partner and chief operating officer at Flagship Pioneering. In this role, Rob is involved in all aspects of Flagship’s processes for originating and developing new companies, and he provides operational and strategic support to key companies. He also plays an important role in Flagship’s strategic planning, talent acquisition and development, and growth management initiatives.

Rob joins the firm after a long tenure at McKinsey & Company, where he was a senior partner. For more than 30 years, he advised the CEOs and boards of leading health care, technology, and consumer companies on corporate strategy, M&A, and improved business unit performance. When he was managing partner of McKinsey’s Stamford office, Rob doubled the partner base and expanded the scope of work into the health care and consumer sectors. Rob was also a member of McKinsey’s Partner and Senior Partner Review Committees, as well as the Partner Compensation and Client Risk Committees. He led the work that shifted McKinsey’s recruiting toward non-MBAs and developed innovative training for the firm’s senior partners. Rob also led significant pro bono work for Save the Children, Americares, Carnegie Corporation, and Fairfield University.

From mid-2015 through 2016, Rob was EVP and chief financial officer at Valeant Pharmaceuticals, where he led the finance, HR, and IT functions. Rob led Valeant’s financial restatement and regained timely reporting status with the SEC.



  • Executive Partner

    January, 2018 - present