Was born in Beirut, Lebanon during the chaos of civil war and foreign invasions. At nine months old, he was adopted by Leo and Sophia Lemonis, a Greek couple living in Miami. He grew up in the automotive industry, as his grandfather owned two of the largest Chevrolet dealerships in the United States.
At age 12, Marcus had his first business: a lawn mowing service, in order to generate money to open a candy business. In his early life he was called “The Mayor,” because he liked to be in charge of everything.
As a child, Marcus attended Epiphany Grade School and then went on to attend Christopher Columbus High School (Miami) prior to moving to Milwaukee, WI to attend Marquette University. At Marquette, he was involved in student government, was a member of the track team and served as the president of the Student Athletic Council. Marcus graduated with a degree in political science in 1995. At graduation, the Rev. Robert A. Wild -President of Marquette - was asked to describe Marcus in one word. That word was “Entrepreneurial”.After graduating from Marquette University Marcus returned to Florida and ran for a seat in the Florida House of Representatives. At the age of 22 and with no political experience, he gained the endorsement of the Miami Herald, though he lost the campaign.
Early in his career Marcus took a job as a sales manager at AutoNation, a Florida-based dealership group in 1997. Two years later, he was promoted to regional Director for the N/NE district. Shortly thereafter, he had a conversation with family friend and auto mogul Lee Iacocca, who suggested Marcus switch to the camping and RV industry, because there had yet to be a defining trailblazer in that arena. In 2003, after realizing the potential for growth the RV industry had, Marcus took his automotive background and started acquiring RV dealerships under the company FreedomRoads. Then in 2006, he merged FreedomRoads with Camping World, the nation’s #1 camping and accessories retailer. Since then, Marcus has bought more than 100 RV companies from mom-and-pop dealerships across the country and turned them into Camping World RV SuperCenters.Recent career[edit source.
In 2010, Marcus combined Camping World with Good Sam Enterprises. The consolidated company has close to 6,000 employees in over 100 cities and will record close to $3 billion in sales in 2013. Marcus attests Camping World and Good Sam’s success to the three P’s: people, process and product. As the CEO of Camping World, Marcus teamed up with NASCAR for the first time in 2004, when the company sponsored driver John Andretti. Three years later, Marcus and Camping World sponsored the then Craftsman Truck Series and re-branded it to the NASCAR Camping World Truck Series, making the company one of the sport’s top three sponsors. Marcus and Camping World also made headlines in 2013, announcing their sponsorship with 19-year-old African-American race car driver Darrell Wallace Jr.. Lemonis was quoted that the "decision to sponsor Wallace was based mainly on his promising talent, not a particular drive for diversity in Nascar. Still, he says, this business decision, like many others, carried “some element of social responsibility.
Marcus is a serial entrepreneur and has helped several troubled businesses in a time of need. Rose’s Bakery & Wheat Free Café was set to close its doors on Christmas Eve of 2012 when Marcus stepped in with an investment that would allow the bakery to remain open. He wrote an initial check for $200,000 to become the majority owner of the business with a commitment of an additional $150,000 investment over the next 18 months. Not only did he save the bakery, but in June 2013 he released a statement unveiling his plans to open a new location in Highland Park, Illinois and expand on the offering. Also in June 2013, Marcus announced plans to open a cold press juicery retail location aptly named "Juice ONE." The new test concept was developed through his holding company, "A Better Life," and was motivated by his ongoing lifestyle goals to eat cleaner and consume vital nutrients.
Marcus was featured on two episodes of NBC’s Celebrity Apprentice  In 2011, he gave each team two Camping World RVs and challenged them to stage an “experience” in mid-town Manhattan
In 2012, Marcus challenged the contestants to write a 90-second jingle for Good Sam’s Roadside Assistance program.
In the summer of 2012, Marcus appeared on an episode of ABC’s Secret Millionaire where he returned to his hometown of Miami to help three different organizations making a difference in the community. The charities Marcus donated time and money to were: National Voices for Equality, Education and Enlightenment, an anti bullying organization; New Journeys, a transitional home for young women; and Neat Stuff, an organization that provides new clothes, shoes and accessories to meet the basic needs of abused, neglected and distressed children.
In 2013, Marcus became the star of the CNBC reality show "The Profit". The show features Marcus on the hunt for promising, but faltering small businesses. He puts his own money on the line to save the business and make himself a profit. The show teaches business principles and features Power-Point ready tips in each episode.Accomplishments
In 2007, RV Business Magazine named Marcus "Newsmaker of the Year." The magazine, regarded as the industry leader, recognized him at the age of 34 for having “more impact on the industry than any single individual or company in recent memory as an agent of change and retail consolidation.”
Crain’s Chicago Business featured him in their 2005 edition of “40 under 40” and in 2008, Ernst & Young named him "Entrepreneur of the Year."
Marcus' philanthropic habits started years before becoming a successful entrepreneur. At Marquette, he served as the president of the Student Athletic Committee and planned a citywide clothing drive to help the homeless of Milwaukee get a head start before winter.Over the years, Marcus has contributed his time and money to the following organizations: St. Jude Children’s Research Hospital. National Voices for Equality, Education and Enlightenment. New Journey’s Transitional HomeNeat StuffMarquette University (major donor) Ravinia Festival Association (Board of Trustees)Lincoln Park Zoo (sponsor)Photocharity (Bridge Program underwriter)Zacharias Sexual Abuse Center (sponsor) marcus’ philanthropic efforts trickled into his company as well. Under his direction, Camping World and Good Sam launched “Project Good Samaritan” as part of their 2013 goal to foster corporate responsibility, which requires the team of nearly 6,000 employees to volunteer 32 hours per year (eight per quarter) to causes that are meaningful to them.