Bart Starr, the gritty, record-setting Green Bay Packers quarterback who became coach Vince Lombardi’s star pupil and field marshal in the 1960s, winning five NFL championships and the first two Super Bowls, died May 26 in Birmingham, Ala. He was 85.

His death was announced by the Packers, who said he had been in poor health since suffering two strokes and a heart attack in 2014.

Introspective and unassuming, with a reputation as Mr. Nice Guy, Mr. Starr was an unlikely success in the smash-mouth NFL. “When I first met him he struck me as so polite and so self-effacing,” Lombardi once wrote, “that I wondered if maybe he wasn’t too nice a boy to be the authoritarian leader that your quarterback must be.”

Drafted in 1956 by the Packers with the 200th pick, Mr. Starr received little playing time before Lombardi took over the team in 1959. He went on to anchor a balanced offensive attack that helped make Green Bay the most successful football team of the 1960s, at a time when the NFL was dominated by the running game and plays were typically called by quarterbacks in the backfield rather than coaches on the sidelines.

“The ’60s will be described as the decade in which football became the number one sport in America, in which the Packers were the number one team, and Bart Starr was proudly the number one Packer,” President Richard M. Nixon said at a 1970 ceremony honoring Mr. Starr.

Although he was never as flashy as Johnny Unitas of the rival Baltimore Colts, Mr. Starr established himself as one of the league’s most accurate passers and gutsiest players, securing his legacy of late-game heroics with a quarterback sneak in the final seconds of the 1967 NFL championship, later known as the “Ice Bowl” for its brutal cold conditions.

Raised in Alabama, where his disciplinarian father demanded he play football or tend the family garden, Mr. Starr honed his accuracy by throwing balls through a tire erected on a wooden frame. He led the NFL in completion percentage four times, notching a career average of 57.4 percent, and set a record when he threw 294 straight passes without an interception.

Until Tom Brady won his sixth title with the New England Patriots this year, no quarterback had won more championships than Mr. Starr, who led the Packers to NFL glory in 1961, 1962, 1965, 1966 and 1967. He remains the only quarterback to have won three consecutive league titles.

Mr. Starr was also named the MVP in 1966, and was the MVP of the first two Super Bowls (then known as the AFL-NFL World Championship), beating the Kansas City Chiefs in 1967 and the Oakland Raiders in 1968. He retired following the 1971 season and coached Green Bay from 1975 until his dismissal in 1983, compiling a 52-76-3 record — a disappointment, but one that scarcely seemed to affect his standing among Packers fans.

The team retired his No. 15 jersey in 1973, and Mr. Starr was inducted into the Pro Football Hall of Fame four years later, joining Lombardi as well as teammates that came to include running backs Jim Taylor and Paul Hornung, right guard Jerry Kramer, center Jim Ringo and tackle Forrest Gregg, who died in April.

Mr. Starr once remarked that aside from playmaking ability, no quarterback could be successful without being able to convince his teammates “to go to the gates of hell with him.” As a Packer, he rarely played in conditions resembling a fiery inferno — but instead showed his mettle in the Ice Bowl, often cited as the coldest game in NFL history, on New Year’s Eve 1967.

In a rematch of the previous year’s NFL championship game, the Packers faced off against coach Tom Landry’s Dallas Cowboys, known for their “Doomsday Defense.” The kickoff temperature at Lambeau Field was 13-below, with a wind chill of 36-below — so cold that referees shouted in lieu of using metal whistles, which stuck to their lips. Several players were treated for frostbite, and one of the 50,000 fans in the stands died of exposure.

Mr. Starr faced a 17-14 deficit with less than five minutes to play, and he pieced together a methodical drive that brought the Packers within inches of the end zone. With 16 seconds remaining, he called one last timeout and walked to the sideline to discuss the play with Lombardi. In lieu of kicking a field goal to tie it, or handing the ball to his running back in slick conditions, Mr. Starr suggested that he run it in himself.

“Then run it,” his coach said, “and let’s get the hell out of here.” (Lombardi later quipped that he couldn’t bear for the team’s fans to shiver through overtime, if the Packers simply tied it.)

In subsequent interviews, Packers players recalled that Mr. Starr never said he was going to keep it himself. The team reportedly didn’t have a quarterback sneak in the playbook. But as the Cowboys defense prepared for a pass play, Mr. Starr took the snap and dove ahead behind Kramer and center Ken Bowman, plunging into the end zone with 13 seconds to go.

His touchdown became an iconic moment for the Packers, even as some commentators and opposing players questioned Mr. Starr’s play call. Boyd Dowler, a Packers receiver, once recalled that a Cowboys player told him that it was a strategic mistake, “because if Bart wouldn’t have gotten in, we wouldn’t have enough time for another play.”

“Well, who knows that?” Dowler said in an interview with the Milwaukee Journal Sentinel. “It’s subjective. I told him, ‘I was in the huddle for nine years with Bart and in all those games I don’t think he ever made a bad call. So that’s so much for your opinion.’ ”

Bryan Bartlett Starr was born in Montgomery, Ala., on Jan. 9, 1934. His mother was a homemaker, and his father was an Air Force master sergeant and veteran of World War II.

“I was not allowed to express my own views or disagree with him,” Mr. Starr once wrote. “I never even raised my voice.”

Mr. Starr was 13 when his younger brother, Hilton — known as the tougher, more aggressive player in family football games — died of tetanus after stepping on a dog bone. His father soon urged the scrawny Mr. Starr to match his brother’s intensity on the field, and with tutoring from University of Kentucky standout Babe Parilli, Mr. Starr became a high school all-American.

At the University of Alabama, he led the Crimson Tide to a Southeastern Conference title in his sophomore season and was proclaimed “the best passer” in school history by coach Harold “Red” Drew.

But Mr. Starr, who also played as a punter and safety, suffered a back injury during a hazing incident — at the time, it was written off as a training accident — and missed most of his junior and senior seasons. He was slated to serve in the Air Force after his first year with the Packers but failed his medical examination as a result of the injury, according to the news website

Mr. Starr’s Green Bay teams initially struggled, going 8-27-1 before Lombardi was named head coach. Mr. Starr then battled Lamar McHan to become the starting quarterback, finally securing the job five games into the 1960 season, when he completed a comeback victory over the Steelers. He led the team to the NFL championship that year but lost to the Philadelphia Eagles, 17-13.

It was the last time the Packers lost a playoff game under Mr. Starr, who later owned car dealerships, worked as a real estate investor and supported organizations including Rawhide Boys Ranch, a Wisconsin charity for at-risk teenagers. The Bart Starr Award is now given to an NFL player for outstanding character and leadership.

Survivors include his wife of 65 years, the former Cherry Morton; a son, Bart Starr Jr.; and several grandchildren. He is predeceased by another son, Bret Starr, who died in 1988 as a result of cocaine use.

Although Lombardi is often cited as the greatest coach in football history, it was Mr. Starr, some teammates said, who deserved much of the credit for their success on the field.

“The dirty little secret of those days,” said Packers offensive tackle Steve Wright, according to “Bart Starr: America’s Quarterback and the Rise of the National Football League” (2011) by Keith Dunnavant, “was that during the week it was Lombardi’s team, but on Sunday it was really Starr’s team.”