Waitt was born and raised in Sioux City, Iowa and attended the University of Iowa and left without earning a degree. Waitt and Mike Hammond started Gateway 2000 on September 5, 1985 with a $10,000 loan secured by Waitt's grandmother. The Company began on Waitt's father's cattle ranch in Sioux City, Iowa, moved to Sergeant Bluff, Iowa and later to North Sioux City, South Dakota, where they continued to develop their "down-home" branding, complete with computer boxes that patterned with black and white Holstein cow patterns.
Waitt led a move of the company's headquarters from South Dakota to Poway, California in 1998. Mr. Waitt released the reins as CEO of Gateway in late 1999 to Jeffrey Weitzen, but returned to the post in January 2001.
In 2004, after the acquisition of eMachines, Waitt turned over day-to-day operations of Gateway and the title of CEO to Wayne Inouye, the former CEO of eMachines. In May 2005, he resigned as chairman of the company, ending a near 20-year run with the company he co-founded.
Waitt has been featured on numerous lists by Forbes magazine. He has held a spot on both the Forbes 400 Richest in America as well as Forbes list of the World's Billionaires. He has also been listed on Fortune Magazines "40 Richest Under 40", a list of the 40 wealthiest self-made Americans under the age of 40 in the United States. The 2008 Forbes 400 List listed Waitt with a net worth estimated at $1.4 billion. Waitt fell off the Forbes 400 list in 2009 with a net worth estimate of $900 million. Forbes speculated that the drop from the previous year was as a result of "souring real estate" and a divorce settlement.
According to the September 2002 issue of Fortune Magazine, Waitt sold $1.1 billion in Gateway stock during the dot-com era. In August 2007, Gateway was acquired by Acer Inc. for $1.90 per share or $710 million.
Labeled a maverick by national business and technology publications, he has gone on to form four enterprises that are his chief interests: Avalon Capital Group, Inc., a wholly owned, billion-dollar private investment company with diverse interests in technology, health care, energy, finance, and real estate; and the Waitt Foundation, Waitt Institute and Waitt Institute for Violence Prevention, nonprofit organizations dedicated to the improvement of mankind’s knowledge through historical and scientific exploration.
Mr. Waitt resides in La Jolla, California with his family.
Through the Waitt Foundation, Waitt has become one of America’s 50 most generous philanthropists, according to Business Week. The Foundation funds partnerships and projects, sometimes in conjunction or collaboration with the Waitt Institutes, that seek a deeper understanding of human history and improve mankind’s knowledge through historical and scientific exploration.
Established in 1993, the Foundation initially focused on domestic violence prevention and community development, knowing that building stronger families and societies will help foster the vision of a better world. The creation of the Waitt Institutes in 2005—the Waitt Institute, and the Waitt Institute for Violence Prevention—has allowed the Foundation to broaden its program interests to the global community.
Waitt serves as the Chairman of the Founding Fathers campaign of the Family Violence Prevention Fund, just one of the efforts that he supports in the fight to prevent domestic violence. Waitt was appointed by Congress to serve on the Advisory Commission on Electronic Commerce and has served on numerous other corporate and philanthropic boards of directors, including the Advisory Council of the National Geographic Society and as Vice Chair of the Board of Trustees of the Salk Institute for Biological Studies.
On 1 May 2008, the Salk Institute for Biological Studies announced the grant of $20 million from the Waitt Foundation to fund the creation of an Advanced Biophotonics Center. On 18 December 2008, the William J. Clinton Foundation released a list of all contributors. It included Theodore Waitt, who gave between US$10–25 million. On April 23, 2011, the Sioux City Public Museum had its grand opening. $4 million of its $13 million development budget was donated by the Waitt Foundation.
- "Early History of Gateway 2000". Free Encyclopedia of Ecommerce. Archived from the original on May 25, 2007.
- "Waitt gives up CEO role". CNET Networks date = 2004-03-11.
- "Waitt leaves Gateway board". CNET Networks date = 2005-05-19.
-  Forbes 2009 List
-  Fortune, September 2, 2002
-  MSNBC, August 27, 2007
-  Wired, May 1995
- "The Top Givers". Business Week. 2003-12-01. Archived from the original on 2008-03-27.
- "Waitt Foundation - Our History". Archived from the original on 2008-03-27.
- "Board of Trustees, Salk Institute for Biological Studies". Archived from the original on 2008-03-27.
- "Waitt Foundation grant to Salk Institute for Biological Studies - Advanced Biophotonics Center".
- Contributor Information to the William J. Clinton Foundation
- "Waitt Foundation grant to Sioux City Public Museum".