John Mars

John Mars
Born	15 10 1935 (age 91 years old (as of 2026) )
Occupation	businessman
Known for	Co-owner and former co-president of Mars, Incorporated
Spouse(s)	Adrienne Mars
Education	The Hotchkiss School; Yale University (BA)

American businessman; former co-president and co-owner of Mars, Incorporated

John Mars (born 15 October 1935) is an American businessman who, with his brother Forrest Mars Jr., ran the family company Mars, Incorporated as co-president from 1973 until the end of the 1990s. Forbes estimates that he owns about one-third of the company.^[1]^[2] On 20 October 2026 the Forbes Real-Time Billionaires list ranked John Mars 36th in the world (tied with his sister Jacqueline Mars), with an estimated net worth of US$50.35 billion; Forbes lists the source of wealth as Candy, pet food.^[1]^[3] In the annual World's Billionaires list published in 2026, Forbes had ranked John Mars 38th, at US$49.1 billion.^[4]

Family background and education

John Mars is a grandson of Frank C. Mars, who founded the company in Tacoma, Washington, in 1911, and the son of Forrest E. Mars Sr. Forrest Sr. joined the company in 1929 and in 1932 moved to the United Kingdom to start a business there. He returned to the US and set up M&M Limited in Newark, New Jersey.^[5] Forbes lists John Mars's education at the Hotchkiss School and Yale University.^[1]

Business career

The Observer reported that John Mars and Forrest Jr. became co-presidents in 1973 and ran the company together for more than two decades. Forrest Jr. retired in 1999 and John in 2001, after which outside executives took over day-to-day management.^[2] Forbes says the siblings inherited their stakes when their father died in 1999, and that the business, with about US$65 billion in sales, makes pet-care brands such as Pedigree and Whiskas and foods such as Ben's Original rice as well as confectionery.^[1] In December 2025 Mars completed its acquisition of Kellanova.^[6]

Wealth

Forbes gives the source of his wealth as candy and pet food. It estimates that he and his sister Jacqueline each own about a third of Mars, and that the four daughters of their late brother Forrest Jr. are believed to own most of the rest.^[1] The Observer reported that Forbes estimates each of the four daughters owns about 8%.^[2]

Wealth history

Forbes has included this entry in its annual World's Billionaires list in 26 of the editions from 2001 to 2026 checked for this profile, starting with 2001. The table gives the rank and estimated net worth in each annual list, and, where applicable, the rank and estimate in the Forbes 400 list of the richest Americans.^[4]^[1]

Forbes estimates by list year
Year	World's Billionaires rank	Net worth (US$ bn)	Forbes 400 rank	Forbes 400 net worth (US$ bn)
1996	–	–	27	3.0
1997	–	–	30	3.3
1998	–	–	29	4.0
1999	–	–	27	5.5
2001	31	9.0	18	9.0
2002	26	9.0	13	10.0
2003	21	10.0	15	10.4
2004	27	10.4	17	10.0
2005	32	10.4	19	10.0
2006	44	10.0	21	10.5
2007	58	10.5	19	14.0
2008	46	14.0	20	12.0
2009	43	9.0	19	11.0
2010	52	11.0	26	10.0
2011	81	10.0	20	13.8
2012	52	13.8	16	17.0
2013	36	17.0	15	20.5
2014	31	20.0	19	22.0
2015	22	26.6	18	23.4
2016	27	23.4	16	27.0
2017	26	27.0	16	25.5
2018	34	23.6	18	24.0
2019	33	23.9	19	29.7
2020	29	24.7	20	29.0
2021	48	31.3	21	31.8
2022	41	31.7	19	37.0
2023	31	38.3	19	38.9
2024	35	38.5	19	47.6
2025	33	42.6	22	42.2
2026	38	49.1	21	50.3

Philanthropy

Forbes describes John and Adrienne Mars as noted supporters of the Smithsonian Institution.^[1] The Smithsonian's 2015 annual report said their gift had endowed two directorships, one at the National Air and Space Museum and one at the National Zoological Park's Smithsonian Conservation Biology Institute, each called the John and Adrienne Mars Director. It added that the couple's support for the Smithsonian dated from 1978 and covered eight of its museums, research centres and programmes.^[7] Separately, in 2012 the company, Mars, Incorporated, gave US$5 million to the National Museum of American History for the "American Enterprise" exhibition in the Mars Hall of American Business.^[8]

Inside Philanthropy reported in 2014 that John Mars had also supported the Fred W. Smith National Library for the Study of George Washington at Mount Vernon. It said that he and Forrest Jr. gave US$2 million to Yale to endow a professorship in ethics, politics and economics, and that he once gave US$5 million to Wheaton College, which his wife attended. It also said he lived in Wyoming and was one of three directors of the family's Mars Foundation, alongside his siblings.^[9]

Political activity

Inside Philanthropy reported in 2014 that the three Mars siblings had given to the Republican Party.^[9] An OpenFEC query for itemised individual contributions under the name "Mars, John" for the 2022–2026 cycles found no records that could be confidently attributed to him.^[10]

Controversies and legal issues

No legal proceedings or controversies involving him personally were found in the sources checked.

International and political links

This section uses the same ten headings for every profile in this series. Only specific, sourced actions are included; company-level and foundation-level actions are labelled as such. Where nothing was found, the entry reads "No documented involvement found in sources checked."