Founded in 1922 by Charles Robert Allen, Jr., he was soon joined by his brothers, Herbert A. Allen, Sr. and Harold Allen. Today, the firm is generally regarded as the premier investment house in the media and entertainment sector despite having only a small staff (estimated at 170 employees).

Allen & Company, which is currently run by Herb Allen, nephew of the founder, generally shies away from publicity and does not maintain a website or issue press releases, with the exception of the extendsive media procured for its annual conference evidenced by its allowance of access to the conference by financial media properties such CNBC, WSJ and others to cover its event.

In 1973, Allen & Company bought a stake in Columbia Pictures. When the business was sold in 1982 to Coca-Cola, they netted a significant profit. Since then, Herbert Allen, Jr. has had a place on Coke's board of directors.
Since its founding in 1982, the Allen & Company Sun Valley Conference regularly draws such heavyweights as Bill Gates, Warren Buffett, Rupert Murdoch, Barry Diller, Michael Eisner, Oprah Winfrey, Robert Johnson, Andy Grove, Richard Parsons, Donald Keough, and many others. Excite quotes a "media mogul": "Deals just don't get done in Hollywood unless Allen & Co. has a hand in it."

Allen & Co. was one of the underwriters for the Google initial public offering, and have been retained to assist the ownership of the New York Mets in obtaining a strategic partner