Richard Bull, left, with Alison Arngrim in 2011. Mr. Bull played shopkeeper Nels Oleson, and Arngrim played his daughter Nellie on “Little House on the Prairie.” (AP Photo/Courtesy Alison Arngrim) (AP)

Richard Bull, the television character actor known to millions of TV viewers as Nels Oleson, the frontier shopkeeper in the long-running drama “Little House on the Prairie,” died Feb. 3 at a hospital in Woodland Hills, Calif. He was 89.

The cause was complications from pneumonia, said his wife, actress Barbara Collentine Bull.

Inspired by the autobiographical writings of Laura Ingalls Wilder, “Little House on the Prairie” aired on NBC from 1974 to 1983 and continued for decades in syndication, winning the enduring affection of its audiences.

The wholesome series, which starred Michael Landon as family patriarch Charles Ingalls and Melissa Gilbert as his daughter Laura, transported viewers to the town of Walnut Grove, Minn., in the American West of the late 1800s.

There were log cabins, rabbit stew and stage coaches — and there was Oleson’s Mercantile general store run by Nels and his hen-pecking wife, Harriet, played by Katherine MacGregor. (Alison Arngrim played their spoiled daughter, Nellie.)

Mr. Bull, a veteran actor whose previous roles included the doctor in the TV series “Voyage to the Bottom of the Sea,” carefully shaped the persona of his ever-docile character Nels.

“When we began the series,” he once told the High Point, N.C., Enterprise, “Michael Landon told me he didn’t want Oleson to be a stupid character, and neither did I. He’s a man who can function quite normally when he is with other people. It’s merely when she’s around I don’t seem to function as well,” Mr. Bull said, referring to his onscreen wife.

Mixed in with the everyday pleasures and travails of life on the frontier were occasional surprises. In one episode, Nels learns that the fat lady in a traveling circus is his sister.

In another, he becomes exasperated with his wife’s overbearing ways, seeks refuge on the road as the proprietor of a traveling store, and becomes smitten with a younger woman.

Mr. Bull expressed concern about such a plot point, which he feared might taint his character’s reputation. His fears were never realized, and Nels Oleson remained a fan favorite.

“Well, it was about time,” he was told by a female viewer who saw the episode, and who happened to be a nun, according to a report in the Brandon Sun of Manitoba, Canada. “You deserved a little change.”

Richard William Bull was born on June 26, 1924, in Zion, Ill., and spent part of his adolescence in Chicago. He described himself as a “movie nut” from a young age. During high school, he enrolled at the drama school at Chicago’s Goodman Theatre. He was “hooked,” he said.

After service in the Army Air Forces during World War II, Mr. Bull returned to Chicago, where he met Barbara Collentine. They were married in 1948 and pursued their acting careers in New York before settling in California.

Before joining the “Little House” cast, Mr. Bull appeared on television shows including “Perry Mason,” “The Fugitive,” “The Alfred Hitchcock Hour,” “The Andy Griffith Show,” “Bewitched,” “Peyton Place” and “Bonanza.”

Later in his decades-long career, he was cast in programs including “Hill Street Blues,” “Highway to Heaven” (featuring Landon as a probationary angel), “Designing Women” and “ER.” His film appearances included “The Thomas Crown Affair” (1968) with Steve McQueen and, more recently, the TV movie “Normal” (2003) starring Jessica Lange and Tom Wilkinson.

In addition to his screen acting, Mr. Bull performed frequently on stage with his wife in works such as James Goldman’s “The Lion in Winter.” She is his only immediate survivor.

He disagreed with critics who found “Little House” too earnest. “I think,” he once told the Wisconsin State Journal, “its idealism is a good antidote to life as we have to live it.”