Johan Weidner, born to Dutch parents, grew up in Collonges, France in the Ain département near the Swiss border where his father served as the minister of the Seventh-day Adventist Church. Following his education at French public schools, he studied at the Seventh-day Adventist Seminary in Collonges, and then pursued a degree in law and in business at the University of Geneva and at the Sorbonne in Paris, France.
In 1935, he established a textile import/export business in Paris, where he was living at the outbreak of World War II. With the subsequent German occupation of France he went south to the city of Lyon where he helped organize the "Dutch-Paris" underground network to aid anyone who needed to escape from the Nazis. In Paris, his sister Gabrielle Weidner and other volunteers helped coordinate escapes. As one of the significant contributors to French Resistance, Weidner's escape network would be responsible for the rescue of at least 1,000 persons, including 800 Jews and more than 100 downed Allied airmen.
In early 1943 he was arrested and brutally interrogated by the Gestapo but revealed nothing and was eventually released. However, another member of his group was taken by the Gestapo and under torture revealed the names of many key members of the Underground including Weidner's sister. As a result, a large number of the groups members were arrested. Gabrielle Weidner was detained by the Gestapo in Paris and after being interrogated and viciously tortured, she was shipped to Ravensbrück concentration camp in Germany where she suffered horribly and died of malnutrition.
Johan Weidner was arrested by the Germans a second time and was placed on a train with other prisoners for shipping to a concentration camp to be used as slave labor. However, during the trip, he jumped off the train and made his way to the safety of neutral Switzerland. From there he escaped to England and was part of the Dutch army formed in Britain and fought with that unit during the final months of the war. After the war, he served in the Dutch diplomatic service. In 1955 he emigrated to the United States, eventually settling in California where he operated a chain of health food stores.
For his War efforts, Johan Weidner was awarded the United States Medal of Freedom, made a member of the Order of the British Empire, the Dutch Order of Orange Nassau and the Dutch Medal of Resistance. The government of France honored him with the Croix de Guerre and Medaille de la Resistance, and the Legion of Honor. The government of Belgium made him an Officer of The Order of King Leopold.
At the 1993 opening of the United States Holocaust Memorial Museum in Washington, D.C he was one of seven persons chosen to light candles recognizing the rescuers. The government of Israel honored Weidner as part of the gentiles designated as "Righteous Among the Nations" at Israel's national Holocaust Memorial, Yad Vashem where a grove of trees was planted in his name on the Hill of Remembrance along the Avenue of the Righteous. Also in 1993, the Atlantic Union College in South Lancaster, Massachusetts, established "The John Henry Weidner Center" for the Cultivation of the Altruistic Spirit.