Tennis commentator Bud Collins at Wimbledon in 1993. (GILL ALLEN/ASSOCIATED PRESS)

Bud Collins, widely considered the country’s leading voice and foremost authority on tennis, who helped popularize the sport through his writing, television commentary and infectious enthusiasm, died March 4 at his home in Brookline, Mass. He was 86.

He had complications from Parkinson’s disease and dementia, said his wife, Anita Ruthling Klaussen.

Mr. Collins, who was named to the International Tennis Hall of Fame in 1994, was a sports columnist at the Boston Globe for almost 50 years and was one of the first sportswriters to make the transition to television.

During his 35 years with NBC, Mr. Collins provided piquant and sometimes irreverent analysis at major tennis tournaments around the world, becoming almost as famous as Martina Navratilova, Jimmy Connors, Pete Sampras and other stars of the sport.

In 1979, he helped inaugurate NBC’s “Breakfast at Wimbledon” broadcasts, quickly winning renown for his witty commentary and his wardrobe of garishly bright trousers.

Mr. Collins was a modestly talented tennis player in his youth — he once won a national mixed-doubles title — and had been a college coach. But in his early years as a sportswriter, he covered baseball, basketball and boxing, and he didn’t find his niche as a tennis writer until 1963, when the Globe sent him to the Davis Cup matches in Australia.

“I went and found a great game, but a very stuffy game,” he told the Miami Herald in 1985. “I wanted to have fun, so I covered tennis the same way I covered other sports. And I used the same approach when I began to broadcast tennis.”

Without giving up his column in the Globe, Mr. Collins began to cover tennis on Boston’s public television station, WGBH, in the mid-1960s. He later moved to CBS and then to NBC. In time, he would write books with some of the sport’s greatest players, a memoir and an encyclopedia of tennis that has been in print for more than 30 years.

“There isn’t another American journalist so identified with his sport as Bud is with tennis,” sportswriter Frank Deford wrote in Sports Illustrated in 2007. “He is the very soul of the game — as historian, as authority, as devotee, as enthusiast.”

Mr. Collins often gave players fanciful nicknames that captured their style of play. Chris Evert was “The Ice Maiden.” Bjorn Borg became the “Angelic Assassin.” The Williams sisters, Venus and Serena, were the “Sisters Sledgehammer.”

At major tournaments, Mr. Collins was a familiar presence, often decked out in custom-made trousers in blinding shades of purple, yellow or chartreuse. His prose was almost as colorful as his wardrobe.

When Roger Federer lost a tournament in Rome, Mr. Collins wrote, “Federer left town feeling as though he’d fallen down the Spanish Steps, wondering if he’d encountered a lion left over from the Coliseum.”

Mr. Collins believed his responsibility was to take readers and viewers inside the sport, but some people considered him either too flippant or, by contrast, too probing.

“I think all sports broadcasters talk too much,” Mr. Collins said in 1985, including himself in their number. “I can’t help it if I get on some people’s nerves. I’m doing the job the only way I know how.”

Arthur Worth Collins Jr. was born June 17, 1929, in Lima, Ohio. He grew up in Berea, Ohio, where his father was athletic director at what was then Baldwin-Wallace College.

Mr. Collins attended Baldwin-Wallace, where he played tennis and worked on the student newspaper. After graduating in 1951, he served in the Army, then moved to Boston to pursue graduate studies in journalism at Boston University. Before writing his thesis, he joined the staff of the Boston Herald. (He was belatedly awarded his master’s degree in 2009.) He joined the Globe in 1963.

Beginning in the late 1950s, Mr. Collins spent several years as the tennis coach at Brandeis University, where one of his players was Abbie Hoffman, the future radical activist. Hoffman’s approach to tennis, Mr. Collins recalled, was very conservative.

In addition to tennis, Mr. Collins covered many of Muhammad Ali’s heavyweight fights in the 1960s and 1970s, and he wrote about politics and the Vietnam War. For 25 years, he had a travel column in the Globe.

“If I had to choose between TV and writing,” he said in 1994, “I’d probably choose writing.”

Frustrated that there was no comprehensive history of tennis, Mr. Collins published an encyclopedia of the sport in 1980. The most recent edition of what is now “The Bud Collins History of Tennis” runs to almost 800 pages.

His first marriage, to Palmer Collins, ended in divorce. He was predeceased by a longtime partner, Judy Lacy, whose son he helped raise. Mr. Collins’s second wife, Mary Lou Barnum, died in 1990.

Survivors include his wife of 21 years, photographer Anita Ruthling Klaussen of Brookline; a daughter from his first marriage; six stepchildren; and 11 grandchildren.

After 35 years at NBC, Mr. Collins was let go in 2007. He then went to ESPN and continued writing for the Globe until 2011. He made his final public appearance last year, when the media center at the U.S. Open facilities in Forest Hills, N.Y., was named in his honor.

Most players liked Mr. Collins’s nicknames, but on occasion something was lost in translation. When he dubbed the notoriously temperamental Romanian tennis star Ilie Nastase the “Bucharest Buffoon,” Nastase confronted Mr. Collins, asking, “What means buffoon?”

“Just an American term of endearment,” he replied.