In 1991, his father started an independent investment firm with Progressive capital called Securities Advisors, Inc. (SAI), which Al owned and managed until 2001.

[5] His father, Alfred "Al" Lerner, had been appointed chairman of MBNA Corporation after investing US$ 800 million in the initial public offering (IPO) of the company.

[6][7] During his time at Cambridge, Lerner followed English football, taking an interest in three teams: Arsenal, Fulham and Aston Villa.

The statement to the London Stock Exchange confirmed that 60% of the club's shares, including the 39% stake of Doug Ellis had been sold to Lerner, beating competition from consortia led by Michael Neville, Nicholas Padfield QC, and Athole Still.

Eleven days after the announcement, the LSE confirmed that Lerner had secured 59.69% of Villa shares, making him the majority shareholder.

The BBC reported in September 2006 that Lerner had moved closer to taking full control of the club, after increasing his share to 85.5%.

[12] Lambert was sacked on February 11, 2015[13] and replaced by Tim Sherwood,[14] who saved Villa from relegation in the 2014/15 season and took them to the 2015 FA Cup Final.

blamed Lerner for being inactive and failing to invest significantly since the departure of manager Martin O'Neill in 2010 and also selling their best players.

[25] The Wall Street Journal reported that, between 2007 and 2011, Cleveland Browns Transportation was the most frequent flyer in and out of East Hampton Airport.

[26] In July 2019, a limited liability company whose principal is Randy Lerner purchased property near Stony Hill Road in Amagansett.

The property is protected in perpetuity by a conservation easement granted to the Peconic Land Trust who filed suit against Lerner and the limited liability company after 75 to 125 trees were cut down.