Lucette Destouches, the widow and steadfast defender of Louis-Ferdinand Céline, who was one of the most acclaimed French novelists of the 20th century but whose virulently anti-Semitic writings led the couple into exile in Nazi Germany during World War II, died Nov. 8 at her home in Meudon, France. She was 107.

Her death was confirmed to Agence France-Presse by David Alliot, her friend and biographer.

Ms. Destouches, a ballet and cabaret dancer, met her husband in 1936, when Céline — a nom de plume for Louis-Ferdinand Destouches — was at the height of his fame.

In 1932, Céline published his first novel, “Journey to the End of the Night,” a revolutionary book that looked at life from the bottom up, using the argot of the gutter to express a pessimistic, contemptuous view of the world.

“Céline’s dark nihilism,” novelist Mavis Gallant wrote in the New York Times in 1976, “his use of street language, the undertow of mystery and death that tugs at the novel from start to finish were wildly attractive to both Left and Right; both could read into it a prophecy about collapse, the end of shoddy democracy, the death of sickened Europe.”

Some critics found Céline’s book foul and disgusting; others considered it a work of genius. It became a bestseller and an international sensation.

In 1936, Céline published a second novel, “Death on the Installment Plan,” that drew on his own life: He had been severely wounded in World War I, then became a doctor who traveled the world and later treated patients in a Paris slum.

The novel further secured Céline’s position as a herald of the French avant-garde, a reluctant truth-teller whose visions were alternately comic, apocalyptic, enraged and encrusted with grime. All of life, Céline suggested, was an exercise in futility.

His literary influence extended from Jean-Paul Sartre to Henry Miller, Samuel Beckett, Jack Kerouac, William Burroughs, Albert Camus, Günter Grass and Joseph Heller.

“Céline is my Proust!” novelist Philip Roth once exclaimed, before adding, “to read him, I have to suspend my Jewish conscience, but I do it because anti-Semitism isn’t at the heart of his books.”

Ms. Destouches knew little of Céline when they met at a dance studio where she was rehearsing. He was 18 years older and had been married twice before but was immediately entranced by her.

“I want to spend the rest of my days with you,” he wrote in one of his first letters to her. “I have chosen you to gather my soul when I die.”

A misanthrope who reserved his most malevolent hatred for the Jews, Céline wrote three pamphlets between 1937 and 1941 calling for Jews — and other non-Aryans — to be expelled from France, by death if necessary. His writings were so extreme that even officers in the high command of the German occupying force in France condemned them as “savage, filthy slang.”

Céline and Ms. Destouches were married in 1943. A year later, after Allied forces liberated France from its German overlords, the couple fled their homeland, along with other Nazi sympathizers. They ended up at a medieval castle near the German town of Sigmaringen, part of about 1,400 people who constituted a pro-Nazi government-in-exile.

Céline — or, rather, Dr. Destouches found himself tending to the intestinal ailments and other ills of Marshal Philippe Pétain, the octogenarian leader of the collaborationist Vichy government. Ms. Destouches taught modern dance to women stranded at the castle on the Danube.

In one of his later novels, “Castle to Castle,” Céline described the chaotic world of Sigmaringen, as bombs fell on a collapsing Germany, and the wounded, mad and dispossessed clogged the roads with nowhere to go, as if driven by “a destroying angel, convulsed with laughter.”

After Germany surrendered to the Allies in 1945, Céline and Ms. Destouches were on the move again, this time to Denmark, where they were soon arrested. Ms. Destouches was released after 11 days, but Céline spent 18 months in jail, often complaining about his wife’s spending.

In 1950, Céline was tried in absentia in France and declared a national disgrace. Nevertheless, he and his wife were granted amnesty and returned to France in 1951. They lived outside Paris, with a menagerie that included a pack of large dogs, to keep out any intruders.

“It is Céline who matters,” Ms. Destouches once said. “Me, I am nothing.”

After Céline’s death in 1961, Ms. Destouches taught dance classes and welcomed admirers of her husband’s writing to her home, including Allen Ginsberg, French novelist and Nobel laureate Patrick Modiano and singer and model Carla Bruni, who was later married to French president Nicolas Sarkozy.

“She followed him into the depths of hell with a love, an admiration and an affection that was absolute,” Frédéric Vitoux, one of Céline’s biographers, wrote of Ms. Destouches.

Lucie Georgette Almansor was born July 20, 1912, in Paris. Her father was a bookkeeper and Army officer, and her mother sold clothing.

She began training as a dancer at 14 and performed under the name Lucette Almanzor. She was a member of the corps de ballet of the Paris Opera-Comique and toured the United States and Europe as a cabaret dancer.

For years, she refused to allow her husband’s anti-Semitic tracts to be reprinted. As she grew more impoverished and frail, she sought to have them published, but the French government stepped in to block publication in 2017.

“In France, racism is not an opinion,” a government official said. “It’s a crime.”

Last year, Ms. Destouches sold the house in Meudon that she shared with Céline, but she continued to live there until her death. She never remarried and had no survivors.

“I wasn’t looking to be happy with him,” she said. “All I wanted was to alleviate his sorrow.”