Bestselling author Elizabeth Strout grew up on a dirt road in Brunswick, Maine—a town with a population of only 15,000 at the time. Composed of rocky peninsulas streaking into the sea, Brunswick would become the fertile ground for so many of Strout’s most beloved stories. After moving to New York City, her writing returned to small-town Maine, culminating in her most famous novel, Olive Kitteridge, which won the 2009 Pulitzer Prize for Fiction. Her seventh novel, Olive, Again, will be published in October. She now splits her time between New York City and Maine.

You often use the word “truth” when talking about your work. Why is truth so important in your writing, given that you’re a novelist?

I came across this famous Hemingway quote many years ago: “All a writer needs t...