Tomie dePaola, whose picture-book tales of bullied children, Christian saints and a magically overflowing pasta pot delighted generations of young readers and sold millions of copies, died March 30 at a hospital in Lebanon, N.H. He was 85.

The cause was complications from surgery, said his literary agent, Doug Whiteman. Mr. dePaola had suffered a fall last week at his studio barn in New London, N.H.

A former art and theater teacher, Mr. dePaola published more than 200 picture, pop-up and chapter books in his five-decade career. On at least six occasions, he illustrated 10 or more books in a single year.

His illustrations of tousle-haired children and talking animals were uncluttered and uncomplicated, drawn with bold lines and soft colors in acrylic paints, watercolors, ink and collage — in almost every medium except pastel, Mr. dePaola said, which is “too dusty and makes me sneeze too much.”

Much of Mr. dePaola’s work was inspired by global folklore or by his own Irish-Italian heritage. His most famous picture book, “Strega Nona” (1975), was based on a Brothers Grimm story about a magical vessel capable of cooking a limitless amount of porridge.

Mr. dePaola’s Italian adaptation of the story featured the title character — a friendly enchantress whose name means “granny witch” — and her clumsy helper, Big Anthony, who unintentionally floods their Calabrian town with spaghetti when he utters the incantation: “Bubble, bubble, pasta pot / Boil me some pasta, nice and hot.”

Because “the punishment must fit the crime,” as Strega Nona says, Big Anthony is sentenced to the inhuman task of eating all the leftover pasta.

The book was awarded a Caldecott Honor and later adapted into a musical and animated short film.

Mr. dePaola’s other folk-inspired works included picture books about trolls (“Helga’s Dowry: A Troll Love Story”), Irish giants (“Fin M’Coul: The Giant of Knockmany Hill”) and Native American myths (“The Legend of the Indian Paintbrush,” “The Legend of the Bluebonnet”).

He also illustrated many books with Christian themes, including “The Clown of God” (1978), “Francis: The Poor Man of Assisi” (1982), “Patrick: Patron Saint of Ireland” (1992) and “Angels, Angels Everywhere” (2005).

Mr. dePaola was not considered as groundbreaking as Maurice Sendak, whose 1963 masterpiece “Where the Wild Things Are” changed the very idea of what a picture book for children was allowed to say, or as introspective as Arnold Lobel, who created the Frog and Toad series.

However, Mr. dePaola’s straightforward style and gentle humor made his books widely accessible and easy to digest. Author Barbara Bader, writing in the review journal of children’s literature Horn Book Magazine, called Mr. dePaola the “most mild-mannered of creative personalities.”

Raised Catholic, Mr. dePaola lived for six months at a Benedictine priory in Vermont after college. The order’s library and traditional emphasis on art gave Mr. dePaola a chance to study old masters and to practice his craft by designing Christmas cards and fabrics for the priory’s weaving studio.

Mr. dePaola left, he said, because he was afflicted by chronic headaches and “couldn’t stand the silence.” He later briefly returned to the priory and in the 1960s designed murals, a crucifix and a line of greeting cards for several Benedictine abbeys.

Both his religious and secular work was dominated by what Mr. dePaola called “reverence for family.” Not infrequently, the family in question was his own.

In “Nana Upstairs & Nana Downstairs” (1973), Mr. dePaola adapted the story of two deaths, those of his great-grandmother (“Nana Upstairs”) and then his grandmother (“Nana Downstairs”). Its final images included a picture of the child protagonist, Tommy, standing in front of his great-grandmother’s empty bed, confronted with the reality of her death.

It was drawn directly from memory, Mr. dePaola told the Boston Globe. “I get chills — the hair is already standing up on the back of my neck — when I think of that drawing,” he said. “They had just taken her body away, and my grandmother hadn’t remade the bed, but had taken the sheets off. Just this white space with white light. And then I knew she was gone.”

Six years later he published “Oliver Button Is a Sissy,” about a little boy who “didn’t like to do things that boys are supposed to do.” Mr. dePaola, who was gay, based the story largely on an incident from his childhood, when he was teased and bullied for his love of tap dancing but won over schoolmates and family with a convincing dance performance.

“I was called sissy in my young life,” Mr. dePaola told the New York Times in 1999, “but instead of internalizing these painful experiences, I externalize them in my work.”

Thomas Anthony dePaola (pronounced da-POW-la) was born in Meriden, Conn., on Sept. 15, 1934. His father was a barber who also worked as a union official and liquor salesman. His mother, a homemaker, often read aloud to him and his three siblings. Mr. dePaola would draw pictures to complement the stories, and his parents arranged the attic so he could have a place to paint.

A young Mr. dePaola began spelling his name “Tomie” at the suggestion of a cousin, Irish tenor Morton Downey, who encouraged his drawing and dancing. In his autobiographical chapter book “Here We All Are” (2000), Mr. dePaola recalled Downey telling his mother, “He’s got to have an unusual spelling for his first name so people will remember it!”

Mr. dePaola won local art contests and, on scholarship, received a bachelor’s degree in 1956 from the Pratt Institute in New York. Through a classmate, he discovered the paintings of Matisse, whose simple forms, Mr. dePaola said, he strove to emulate.

“I try to be as clear and simple as I can be in my illustrations,” he told the Globe, “so that the child can tell what is going on and what the emotions are.”

In the early 1960s, amid a short-lived early marriage, Mr. dePaola began teaching art and theater, first in New England and then in the Bay Area of California, where he continued his studies. He graduated in 1969 with a master’s from the California College of Arts and Crafts in Oakland and in 1971 earned a doctoral equivalency degree in art from Lone Mountain College in San Francisco.

In 1965, Mr. dePaola illustrated his first book, “Sound,” a science text by Lisa Miller. “The Wonderful Dragon of Timlin,” the first book he both wrote and illustrated, came out the next year.

His book work, he said, benefited immensely from an art therapy program he enrolled in around that time. “It really got me back in touch with the child that I had succeeded in locking up in a closet,” he told The Washington Post in 1985. “You’re told to grow up, to stop acting like a child. But in a field like mine, if I don’t have direct access to that child, I don’t have access to what I really need.”

What followed was a commercial breakthrough, culminating in three 1973 hits: “Charlie Needs a Cloak,” “Andy, That’s My Name” and “Nana Upstairs & Nana Downstairs.”

He continued teaching until the mid-1980s, when he settled into a 19th-century barn in New London and began focusing exclusively on his books. In 2011, the American Library Association awarded him the Laura Ingalls Wilder Award, praising him for “creating seemingly simple stories that have surprising depth and reflect tremendous emotional honesty.”

Survivors include two sisters.

His work became increasingly autobiographical later in his career, beginning with the chapter book “26 Fairmount Avenue” (1999). The book — which told the story of 5-year-old Tomie moving homes, beginning kindergarten and unintentionally sharing a box of chocolate-covered laxatives with his great-grandmother — won a Newbery Honor and spawned several sequels that followed Tomie into the World War II era.

Mr. dePaola also published “Quiet” (2018), about the importance of mindfulness in a hectic age, and continued his “Strega Nona” series with titles including “Strega Nona and the Twins” (2017).

In one of the books, “Strega Nona’s Magic Lessons” (1982), Mr. dePaola seemed to reflect on the nature of his vocation. “To learn magic and practice it well,” the witch tells her apprentice, “you must learn to see and not to see. You must learn to remember and to forget; to be still and to be busy. But mostly, you must be faithful to your work.”

Ruzzier is a freelance writer.