The actor Ken Kercheval, who has died aged 83, found worldwide fame as Cliff Barnes, who was constantly outwitted by his arch-enemy, JR Ewing, in the TV series Dallas. He and Larry Hagman, who played “nasty” JR, were the only two actors to appear throughout the glossy American soap’s original 13-year, 14-series run from 1978 until 1991. The 1980 “Who Shot JR?” episode was watched by 360 million viewers in almost 60 countries.

The brother-in-law of Bobby Ewing (Patrick Duffy) through the marriage of his sister Pam (Victoria Principal), Cliff believed he and his father, Digger (played successively by David Wayne, Keenan Wynn and David Marshall Grant), had been cheated out of an oil fortune by the Ewings. This led to bitter family feuds, Cliff’s affair with JR’s wife, Sue Ellen (Linda Gray), and his constant attempts to take over Ewing Oil. All were thwarted until the soap’s final run, when Cliff finally gained control of the business. Ironically, when the soap returned for the one-off 1996 TV movie Dallas: JR Returns, he decided to sell the business to Bobby and Sue Ellen. Kercheval reprised the role in the 2012-14 revival of the Dallas series, with the feuding continuing as the Ewings took control of his new business.

Kercheval initially modelled the character of Cliff on the US senator Robert Kennedy, but he and the writers quickly evolved him into “Calamity” Cliff, a bumbling loser out of his comfort zone in the cut-throat oil business. A running joke was his penchant for Chinese takeaways. Nevertheless, said Kercheval, when the programme was at its height: “Cliff Barnes is the only one that JR keeps having to worry about. No matter how he gets Cliff down, he can be assured that he’ll turn round and Cliff will be there.”

Kercheval was born in Wolcottville, Indiana, to Christine (nee Rieber), a nurse, and John, a doctor. After the family moved to the state’s former coalmining city of Clinton, he was educated at its high school, then graduated from Chamberlain-Hunt military academy, Mississippi. He studied music and drama at Indiana University (1953-55) and attended the University of the Pacific in California (1956) before taking an acting course at the Neighborhood Playhouse, New York (1956-58).

Between his early stage roles, Kercheval sold encyclopedias door to door, photographed babies, sold plots at a Jewish cemetery and helped to build sewer tunnels beneath Manhattan. As his acting career developed, he made his Broadway debut as Josh in the musical The Young Abe Lincoln (Eugene O’Neill theatre, 1961). His later Broadway highlights included a role in the original production of Fiddler on the Roof (Imperial theatre, 1964) and replacing Bert Convy as Clifford Bradshaw in Cabaret at the Broadway theatre in 1968.

Kercheval’s TV break came with the part of Dr Nick Hunter in the long-running daytime soap Search for Tomorrow, set in a midwestern American town. He had two runs, 1965-68 and 1972-73. Many small-screen character roles followed, including three in Kojak (1973, 1977 and 1978).

In Dallas he was originally earmarked to play the ranch manager Ray Krebbs, JR Ewing’s illegitimate half-brother, while Steve Kanaly was to take the role of Bobby Ewing. After Duffy was subsequently cast as Bobby, Kanaly switched to that of Ray and Kercheval became Cliff. Shortly after the programme began, Kercheval said he was a recovering alcoholic who had joined a self-help group and given up drinking. “I went through a period of terrible heartache and sought refuge in alcohol,” he said. “I’ve woken up in the gutter a lot of times. I used to drink constantly, hard stuff, beer, anything, a tremendous amount of it.”

In 1985 Kercheval invested in a popcorn business, the Old Capital Popcorn Company. Four years later, off-screen drama came to Lorimar Studios, Culver City, where Dallas was filmed, when Edward Phillips Jr – a former business partner forced out of Old Capital by Kercheval – crashed a truck through the gate, set fire to the vehicle, then killed himself with a shotgun after police surrounded him. It was believed he might have been planning to kidnap Kercheval.

Kercheval played guest roles in other popular American series, from a district attorney in Starsky and Hutch in 1979 to a doctor in Walker, Texas Ranger in 1993. He was also a high school guidance counsellor in the 1991 TV movie I Still Dream of Jeannie, based on the 1960s sitcom I Dream of Jeannie (which starred Hagman).

In 1993, after a lifetime of smoking, Kercheval was diagnosed with cancer; part of his lung was removed the following year. In 2006 he appeared on stage in Britain as the General in a White Christmas musical at the Mayflower theatre in Southampton and the Theatre Royal in Plymouth. He reprised the role at the Lowry in Manchester in late 2012 and early 2013.

Kercheval’s three marriages all ended in divorce. He is survived by five children: Caleb, Liza and Aaron, from his first marriage, to Judith Launt; Asa, from his second marriage, to Ava Fox; and Madison, from his third marriage, to Sheryl Paris.

• Kenneth Marine Kercheval, actor, born 15 July 1935; died 21 April 2019

• This article was amended on 29 April 2019 to correct Kercheval’s marital details