Ben Helfgott, an Olympic weightlifter whose entire life was a show of strength, from his endurance as a teenager in Nazi concentration camps to his exploits on the world’s athletic stage to his later unflagging efforts on behalf of fellow Holocaust survivors, died June 16 at his home in London. He was 93.

His son Maurice Helfgott confirmed his death but did not cite a cause.

Mr. Helfgott first pressed a barbell over his head in 1948, the year he turned 19 when he chanced upon some weightlifters pumping iron in a London park and asked to join them in their exercises.

According to an account published years later in Sports Illustrated, he picked up a 140-pounder and hoisted it into the air. “You’ve never lifted weights?” the coach asked incredulously.

He was a natural athlete. But only three years earlier, Mr. Helfgott, a Polish-born Jew, had been liberated from a Nazi camp, starving and weighing only 80 pounds. Both his parents, one of his two sisters, and 21 of his 24 cousins were murdered in the Holocaust.

He came to Britain in 1945 with a group of child survivors that became known as “The Boys,” although there were many girls among the hundreds of refugees in their cohort. Together, and with the aid of relief workers, they set about rebuilding their lives.

Their story was documented in books including “The Boys: The Untold Story of 732 Young Concentration Camp Survivors” (1996) by historian Martin Gilbert, and the 2020 BBC film “The Windermere Children.”

After encountering the weightlifters in the park, Mr. Helfgott started training after school and soon entered international competitions. He won three gold medals at the Maccabiah Games in Israel – in 1950, 1953, and 1957 – as well as four British weightlifting championships.

In 1956, Mr. Helfgott captained the British weightlifting team at the Melbourne Olympics. At the Opening Ceremonies, which coincided with his 27th birthday, he could scarcely maintain his composure.

“I thought of my parents and of how proud they would have been of me,” the Times of London quoted him as saying. At the end of World War II, “I was at the point of death, but here I was alive and kicking, representing my adopted country. There was sadness but also exhilaration.”

Mr. Helfgott finished 13th in the lightweight category in Melbourne and 18th in the same category at the 1960 Games in Rome, where he again was captain of the British team.

“Whenever I pulled on that [British] vest I wanted to do well,” Mr. Helfgott said, according to the London Daily Telegraph. “I so wanted to win a medal to say thank you to the country that saved me.”

In subsequent years, as he pursued a career as a clothing manufacturer, Mr. Helfgott also became a spokesman and champion of Holocaust survivors, in particular those who had arrived with him in Britain.

He helped found and promote the ’45 Aid Society, a British charitable organization established in 1963 to support survivors who needed assistance and, in the description of its mission, to “give back to the society that had welcomed them.”

Mr. Helfgott was for years chairman of the group, one of many organizations and commissions he served in his effort to preserve the memory of the Holocaust.

He was awarded a knighthood by Queen Elizabeth II in 2018. “His legacy,” Prime Minister Rishi Sunak wrote on Twitter after Mr. Helfgott’s death, “is the ultimate triumph over [the] darkness” of the Holocaust.

Mr. Helfgott – British newspapers listed his name at birth as Beniek – was born in Pabianice, a Polish city near Lodz, on Nov. 22, 1929, and grew up in Piotrkow.

He was 9, soon to be 10, when Germany invaded Poland in 1939, marking the start of World War II. Fleeing bombs in Piotrkow, his family went east by horse-drawn carriage to Sulejow, which soon came under aerial attack from incendiary explosives. With its many thatched-roof homes, the town was swiftly set ablaze.

People “were blindly running, as were cats, dogs, horses, and cows, many on fire. They were running, madly, pointlessly, agonizingly,” Mr. Helfgott recalled. He and his family found refuge in a brick house and then in the forest, surrounded by carnage.

They were soon ordered into the Piotrkow ghetto, the first ghetto established by the Nazis in Poland, where some 20,000 Jews were crowded in unlivable conditions. Mr. Helfgott’s father, who had been a partner in a mill, smuggled in flour to help feed the ghetto’s residents, defying the Germans “at every stage,” his son recalled.

Mr. Helfgott’s family survived mass deportation toward the end of 1942. (Ben, as he was always known, was 12 at the time and was left untouched because he had a job at a glass factory.) But months later, his mother and one of his sisters, who had been in hiding, were rounded up with hundreds of other remaining Jews and executed in a nearby forest.

“Within minutes we knew,” Mr. Helfgott recounted. “My father came in, and I looked at his face, and I didn’t have to ask. It was terrible.”

In late 1944, Mr. Helfgott and his father were deported to Buchenwald, the Nazi concentration camp in Germany. Mr. Helfgott was soon transferred to a subcamp, Schlieben, and then to Theresienstadt, in Czechoslovakia, while his father remained at Buchenwald. Mr. Helfgott later learned that his father died days before what would have been his liberation as he tried to escape a death march.

“I go almost crazy when I think about it,” he told Sports Illustrated. “He was killed like a dog and buried like a dog. Somewhere in a hole, and I’ll never know what place he was killed. I just imagine they threw him in a dustbin or buried him in a place where there is no sign of anything.”

Mr. Helfgott was near death himself when Soviet troops liberated Theresienstadt in May 1945.

“Without warm clothing, we were freezing to death,” he told the Times of London. “We were eaten up by the bugs and lice. And worst of all we were steadily becoming demented as a result of starvation rations. Liberation found us in a state of exhaustion and emaciation. We literally lived from hour to hour. It dawned on skeletal bodies and ransacked minds that they were free. But how does one readjust without a family and a home? We suddenly realized we were alone.”

Mr. Helfgott and the other “Boys” were brought to England through the efforts of the Central British Fund, a relief agency for Jewish refugees. Of his first days in England, Mr. Helfgott remembered, in particular, the softness of his bedsheets, a pleasure that he had all but forgotten during the war.

Nearly all of the children were orphans. Some had no surviving family members at all. They had been deprived of years of education and a great part of their childhood. They fought each other for food, even when it was in relative abundance. But in time, they regained a sense of normalcy, going to school and on outings – the first steps in starting new lives.

Mr. Helfgott discovered that his sister Mala was still alive, after having been deported to Ravensbruck and Bergen-Belsen. She, too, eventually arrived in England.

Mr. Helfgott studied economics at the University of Southampton but left his studies to begin his professional career. He retired in his early 50s to dedicate himself to work on behalf of others who survived the Holocaust and the memory of those who did not.

“If I forget,” Mr. Helfgott said, “then I’m not worthy of being a survivor.”

In addition to his work with the ’45 Aid Society, he was the honorary president of the Holocaust Memorial Day Trust, a charity funded by the British government to support Holocaust Memorial Day in Britain, and honorary patron of the Holocaust Educational Trust in London. Mr. Helfgott was also active with the Claims Conference, which seeks material compensation for Holocaust survivors.

He was credited with editing dozens of volumes of testimonies of Holocaust survivors. Gilbert, in an introduction to his book “The Boys,” cited Mr. Helfgott as having supplied the “determination that this story should be told.” Mr. Helfgott was the subject of the book “Ben Helfgott: The Story of One of the Boys” (2018) by Michael Freedland.

For his athletic achievements, he was inducted into the International Jewish Sports Hall of Fame.

Survivors include his wife of 57 years, the former Arza Gordon, and their three sons, Maurice Helfgott, Michael Helfgott, and Nathan Helfgott, all of London; his sister; and nine grandchildren.

Mr. Helfgott saw sports as a means of reconciliation and, at the Olympics, said he sought out friendships with Poles and Germans.

“My Holocaust experience may have hardened me, made me more realistic about human nature, but I was repelled by the evil I witnessed,” he remarked. “I refused to poison my life with revenge and hatred, for hatred is corrosive.”