Cline's grandfather mined for coal with a pickax around Beckley, West Virginia in the early 20th century. At the age of six, Cline's Father, Paul, asked him to fill a paper bag with dirt, paying him a penny for each bag. Cline dug the dirt from under the porch of their bungalow in Isaban, West Virginia. His Father used the dirt bags in mine-blasting. Within two years, their porch had collapsed. According to Cline, his Father had told him to "support the roof better". In 1980, Cline's Father bought out his partner then gave the shares to Cline, who was then 21 years old. At that time, he was studying psychology at Marshall University in Huntington, West Virginia.

Breast cancer claimed Cline's first wife, Sabrina, in 1987. He remarried in 1993, but the relationship with his second wife, Kelly, ended in divorce in 2000. Cline, who has two sons and two daughters, owns a 33,413-square-foot (3,104.2 m) mansion in North Palm Beach, Florida, and a home in his native Beckley, West Virginia, where his 150-acre (0.61 km) property contains a lake, a go-kart track and pastures for his horses, goats and llamas.

In 2005, Foresight Energy built its Williamson longwall mining operation south of West Frankfort in Illinois. Eventually, the coal mining division of the Cline Group acquired Exxonmobil's Monterey No. 1 mine, and developed Sugar Camp, Hillsboro, and the Macoupin complex.

SNL Financial reported in 2008 that Deer Run coal mine in Montgomery County, Illinois, a project of Cline's Hillsboro Energy LLC, would produce up to 8 million tons annually until 2016. In the same report, representatives for Cline said that he was aiming for an annual coal production of 60 million tons from Illinois alone.

On July 20, 2011, Marshall University received a donation of $5 million from the Cline Family Foundation for Sports Medicine research. The donation was announced during a fundraising event held at Cline's Beckley home.

On August 20, 2012, aspiring actor Vivek Shah was arrested for the attempted extortion of Chris Cline, Harvey Weinstein, and three other unnamed individuals. On or around June 26, 2012, Shah threatened to kill members of Cline's family if $13 million was not wired to an offshore bank account. A seven-count felony indictment against Shah was filed in U.S. District Court in Los Angeles during the last week in September 2012, and in 2013 he was sentenced to seven years in prison.

In 2015, Jasper Reserves, L.L.C., owned by Cline, donated $1 million to Super PACs supporting the presidential candidacy of Jeb Bush.

Cline said that humankind will benefit more from cheap and abundant Energy than from overreacting to what he calls minimal increases so far in atmospheric CO₂ and the level of the world’s oceans. In an interview with Bloomberg, Cline said "As far as the social acceptability of coal, I like to think I’m part of supplying the cheapest Energy in America."