#21 (tie) George Roberts
Amount donated in 2012: $50 million
Net worth: $3.7 billion
Beneficiary: Claremont McKenna College
Background: Roberts is a founding partner of Kohlberg Kravis Roberts & Company, an international private equity firm.
Source: The Chronicle of Philanthropy
#21 (tie) Eugene Lang
Amount donated in 2012: $50 million
Net worth: n/a
Beneficiary: Swarthmore College
Background: Lang founded REFAC Technology Development Corporation, a manufacturing and technology-transfer company.
Source: The Chronicle of Philanthropy
#21 (tie) Jeff and Judy Henley
Amount donated in 2012: $50 million
Net worth: n/a
Beneficiary: University of California at Santa Barbara
Background: Henley is chairman of the Oracle Corporation.
Source: The Chronicle of Philanthropy
#21 (tie) Jonathan and Karin Fielding
Amount donated in 2012: $50 million
Net worth: n/a
Beneficiary: University of California at Los Angeles School of Public Health
Background: Fielding is the director of the Los Angeles County Department of Public Health and an investor.
Source: The Chronicle of Philanthropy
#21 (tie) Ernest Scheller Jr. and Roberta Scheller
Amount donated in 2012: $50 million
Net worth: n/a
Beneficiary: Georgia Institute of Technology
Background: Scheller is the chairman emeritus of Silberline Manufacturing.
Source: The Chronicle of Philanthropy
#20 Joshua Rechnitz
Amount donated in 2012: $57 million
Net worth: n/a
Beneficiary: New York City Fieldhouse
Background: Rechnitz is a philanthropist and heir to the fortune of his grandfather, Robert H. Heilbrunn, an investor who died in 2001.
Source: The Chronicle of Philanthropy
#19 Herbert and Florence Irving
Amount donated in 2012: $60 million
Net worth: n/a
Beneficiary: Columbia University Medical Center, NewYork-Presbyterian Hospital
Background: Irving co-founded the Sysco Corporation, a distributor of food service products.
Source: The Chronicle of Philanthropy
#18 Irwin and Joan Jacobs
Amount donated in 2012: $60.05 million
Net worth: $1.5 billion
Beneficiary: Joan and Irwin Jacobs Fund at the Jewish Community Foundation of San Diego
Background: Jacobs is the co-founder of Qualcomm, a wireless-communications company.
Source: The Chronicle of Philanthropy
#17 Wayne and Delores Barr Weaver
Amount donated in 2012: $83.7 million
Net worth: n/a
Beneficiary: Community of Jacksonville, Baptist Health Foundation
Background: Weaver is chairman of Shoe Carnival and his wife, Delores, is managing partner of the John Gorrie Investment Group. They were majority owners of the Jacksonville Jaguars, which was sold last year.
Source: The Chronicle of Philanthropy
#16 Brooke Astor
Amount donated in 2012: $88.8 million (bequest)
Net worth: n/a
Beneficiary: New York Community Trust, Metropolitan Museum of Art, New York Public Library.
Background: Astor, who died in 2007, was a prominent New York philanthropist and the widow of Vincent Astor, an heir to a real estate fortune.
Source: The Chronicle of Philanthropy
#15 John and Jenny Paulson
Amount donated in 2012: $100 million
Net worth: $11 billion
Beneficiary: Central Park Conservancy
Background: Paulson is the founder of hedge fund Paulson & Company.
Source: The Chronicle of Philanthropy
#14 Eli and Edith Broad
Amount donated in 2012: $101.5 million
Net worth: $6.3 billion
Beneficiary: Broad Foundations
Background: Broad is the founder and chairman of homebuilder KB Home Corporation and financial services company SunAmerica. The couple's foundation supports civic programs, contemporary art museums, education, and medical and scientific research.
Source: The Chronicle of Philanthropy
#13 Michael Moritz and Harriet Heyman
Amount donated in 2012: $116.4 million
Net worth: $1.9 billion
Beneficiary: University of Oxford
Background: Moritz is chairman of venture capital firm Sequoia Capital. His wife, Harriet, is a writer and former editor at The New York Times.
Source: The Chronicle of Philanthropy
#12 Phil and Penelope Knight
Amount donated in 2012: $125 million
Net worth: $13.1 billion
Beneficiary: Oregon Health & Science University Foundation
Background: Mr. Knight is a co-founder and chairman of the Nike Corporation.
Source: The Chronicle of Philanthropy
#11 David Koch
Amount donated in 2012: $137 million
Net worth: $31 billion
Beneficiary: Metropolitan Museum of Art, National Museum of Natural History
Background: Koch is the executive VP of Koch Industries, Inc.
Source: The Chronicle of Philanthropy
#10 Guy David Gundlach
Amount donated in 2012: $140 million
Net worth: n/a
Beneficiary: Elkhart County Community Foundation
Background: Gundlach, who died in 2011, was the founder of Hastings Direct, an auto-insurance company he sold in 2006 for more than $220 million.
Source: The Chronicle of Philanthropy
#9 Sheldon and Miriam Adelson
Amount donated in 2012: $143 million
Net worth: $20.5 billion
Beneficiary: Dr. Miriam and Sheldon G. Adelson Medical Research Foundation and the Adelson Family Foundation
Background: Adelson is a major hotel developer in Las Vegas and chairman of the Las Vegas Sands Corporation. His wife, Miriam, is a physician.
Source: The Chronicle of Philanthropy
#8 Carl Icahn
Amount donated in 2012: $150 million
Net worth: $14.8 billion
Beneficiary: Mount Sinai School of Medicine
Background: Icahn is a hedge fund manager and financier.
Source: The Chronicle of Philanthropy
#7 Fred Fields
Amount donated in 2012: $191.5 million (bequest)
Net worth: n/a
Beneficiary: Oregon Community Foundation, Lewis & Clark College
Background: Fields, who died in 2011, was the owner and chief executive of the Coe Manufacturing Company, which he sold in 2000.
Source: The Chronicle of Philanthropy
#6 Mort Zuckerman
Amount donated in 2012: $200 million
Net worth: $2.4 billion
Beneficiary: Columbia University
Background: Zuckerman is the co-founder of real estate investment firm Boston Properties, chairman of U.S. News & World Report, and publisher of the New York Daily News.
Source: The Chronicle of Philanthropy
#5 Sergey M. Brin and Anne E. Wojcicki
Amount donated in 2012: $222.9 million
Net worth: $20.3 billion (Brin)
Beneficiary: Brin Wojcicki Foundation, Michael J. Fox Foundation for Parkinson’s Research
Background: Brin is the co-founder of Google and Wojcicki is the co-founder of 23andME, a genetic-testing company.
Source: The Chronicle of Philanthropy
#4 Paul G. Allen
Amount donated in 2012: $309.1 million
Net worth: $15 billion
Beneficiary: Allen Institute for Brain Science
Background: Allen is the co-founder of Microsoft and the founder of Vulcan investment company.
Source: The Chronicle of Philanthropy
#3 John D. and Laura Arnold
Amount donated in 2012: $423.4 million
Beneficiary: Laura and John Arnold Foundation, education and other public non-profits.
Background: John Arnold is the founder of the Houston-based hedge fund Centaurus Energy and his wife was a corporate lawyer and a businesswoman. Their foundation supports initiatives that improve criminal justice, K-12 public education, and pension systems.
Source: The Chronicle of Philanthropy
#2 Mark Zuckerberg and Priscilla Chan
Amount donated in 2012: $498.8 million
Net worth: $17.5 billion
Beneficiary: Silicon Valley Community Foundation
Background: Zuckerberg, 28, is the founder of Facebook. His wife, Priscilla, is a pediatrician.
Source: The Chronicle of Philanthropy
#1 Warren Buffett
Amount donated in 2012: $3.1 billion
Net worth: $46 billion
Beneficiary: Foundations run by his three children, which support causes from agricultural development to women to social justice.
Background: Buffett is the CEO of Berkshire Hathaway and a well-known philanthropist.
Source: The Chronicle of Philanthropy
