Byron Wien (born 1933) is an American investor and vice chairman of Blackstone Advisory Partners, a subsidiary of The Blackstone Group. In 2001, he retired after 21 years as Chief (later Senior) U.S. Investment Strategist at Morgan Stanley, but retained an advisory position with the company as senior investment strategist. In 2006, Wien was named by New York Magazine as one of the sixteen most influential people in Wall Street. The New York Society of Security Analysts (NYSSA) presented Wien with a lifetime achievement award in 2008.