Education isn't exactly the first industry that comes to mind when people think of the Forbes' list of the world's billionaires. While many ranked near the top, from Bill Gates and Warren Buffet to the Walton family, have their hands in a variety of education interests, the bulk of their wealth was made in other fields.

Believe it or not, however, you can make a billion dollars in education — and these seven men are living proof.

Bertil Hult

Rank: 309

The 75-year-old founder of EF Education First is worth $5 billion and is among the world's richest college dropouts. He founded his business, which originally focused on organizing summer trips to the UK so his fellow Swedish students could learn English, in the basement of his dorm. Part of his impetus to do so: his dyslexia, which made learning via textbooks difficult. 

EF Education First now operates in 53 countries, offering everything from cultural exchanges and educational travel to degree programs. It even has its hands in efforts to rethink standardized testing with its EF Standard English Test, or EFSET.

Sunny Varkey

Rank: 949

Worth $2 billion, Sunny Varkey is founder of GEMS Education. According to Forbes, the company operates 50 private K-12 schools enrolling around 140,000 students worldwide, with its first U.S. school located in Chicago. Another, planned for New York City, is currently held up by legal red tape.

No longer chairman of GEMS, Varkey, per Forbes, earned $350 million last October selling a 20% stake in the company's emerging markets sector.

Ranjan Pai

Rank: 1,118

The Indian doctor and proprietor of Manipal Education & Medical Group is worth $1.7 billion. According to The Economic Times, Manipal's education ventures — the nonprofit Manipal University, also known as Manipal Academy of Higher Education, and Sikkim Manipal University, as well as the for-profit Manipal Universal Learning — are among the most valued names in Indian education. Outside of India, Forbes reports that the company has six institutions spread across Malaysia, Dubai, Antigua, and Nepal. The Manipal Group's site describes Pai as a "young, dynamic CEO and MD" who is dedicated to making sure Manipal University "remains a forward-thinking entity, focused on academic excellence."

Peter Sperling

Rank: 1,415

The only American on this list, Sperling is chairman of Apollo Education Group, which operates for-profit higher education institutions — the University of Phoenix chief among them. His father, John G. Sperling, founded the University of Phoenix in 1973, ultimately innovating the models for continuing education for working adults and online programs that many nonprofit higher ed institutions use today. 

According to Forbes, Sperling, worth $1.3 billion, was a major investor in Apollo until enrollment declines began causing trouble for its stock in 2009, leading him to sell off most of his stake in the company. In 2008, he notably donated $9 million in support of California's Proposition 7, which failed to pass but would have mandated half of the power produced by utilities to come from renewable resources by 2025.

Chang Pyung-Soon

Rank: 1,533

A former insurance salesman, Pyung-Soon founded South Korea's Kyowon Co. in 1985 to sell educational products and services for children. Forbes reports that the company is now said to be among South Korea's largest sales organizations with 30,000 agents selling over 3 million customers everything from home-study and hands-on experience programs to e-books, and its affiliate company Kyowon Kumon employs 13,000 teachers serving 2.1 million members.

The company also does business in living and care, as well as hotel and leisure.

Soichiro Fukutake

Rank: 1,638

The man behind education services company Benesse Holdings is worth $1.1 billion. According to Forbes, Benesse is currently focusing heavily on English-language instruction ahead of the 2020 Tokyo Olympics and Paralympics. The language is also reportedly in consideration to become a mandatory subject in Japan from the fifth grade on. With its October 2014 purchase of Minerva, Benesse now owns around 1,800 English schools for kids.

Beyond education, the Benesse Group offers products and services in the global leadership training, lifestyles, and senior/nursing care industries. The company reportedly offered cash coupons to around 29 million customers following a summer 2014 hacking exposed victims' personal information.

Suat Günsel

Rank: 1,638

Tied in net worth with Soichiro Fukutake, Suat Gunsel is proprietor of Yakin Dogu, or Near East, University, the largest in Northern Cyprus, as well as Girne University. According to Forbes, he also has interests in the hospital, bank, hotel, gas station, molding, plastics, and cable industries under the Yakin Dogu name, as well as a massive land portfolio.