John Alexander Thain is an American businessperson who founded Pine Island Capital Partners LLC and who has been the head of 13 different companies.

He holds the position of Chairman for Pine Island Acquisition Corp. and Chairman for Pine Island Capital Partners LLC.

He is also on the board of 9 other companies.

In the past he held the position of Chairman of CIT Group, Inc., Executive Chairman for Efficient Finance Ltd., President & Chief Operating Officer of The Goldman Sachs Group, Inc., President-Global Banking & Securities Division at Bank of America Corp. Chairman & Chief Executive Officer at Merrill Lynch & Co., Inc. Chairman & Chief Executive Officer at Merrill Lynch, Pierce, Fenner & Smith, Inc. (Old), Chairman & Chief Executive Officer at Merrill Lynch, Pierce, Fenner & Smith, Inc. (Old), Chairman & Chief Executive Officer at Merrill Lynch Canada, Inc. Chairman of Merrill Lynch & Co. Canada Ltd. and Chairman & Chief Executive Officer for Merrill Lynch & Co., Inc. (which are all subsidiaries of Bank of America Corp.), Chief Executive Officer & Director at New York Stock Exchange, Inc., Chief Executive Officer & Director at NYSE Group, Inc. and Chief Executive Officer & Director at NYSE Euronext.

John Alexander Thain received an undergraduate degree from Massachusetts Institute of Technology and an MBA from Harvard Business School.