Contributors include Thelma Adams, Monica Ali, Christie Aschwanden, Dan Baker, PhD, Celia Barbour, Martha Beck, Sister Wendy Beckett, Amy Bloom, Brene Brown, Jessica Bruder, Veronica Chambers, Emma Cline, Lisa Congdon, Pamela Erens, Hilene Flanzbaum, Sue Fliess, Lise Funderburg, Roxane Gay, Elizabeth Gilbert, Marianne Gingher, Anne Glusker, Neil de Grasse Tyson, Heather Greenwood Davis, Lara Kristin Herndon, Roger Housden, Joyce Johnson, Lila Keary, Andrea Lee, Beth Levine, Mark Leyner, Valerie Monroe, Catherine Newman, Mary Oliver, Meghan O'Rourke, Victoria Redel, Gretchen Reynolds, Shonda Rhimes, Jane Smiley, Kathryn Sullivan, Abigail Thomas, Justine Van Der Leun, Patricia Volk, Lauren F. Winner, Jessica Winter.

O's Little Book of Happiness features writing that has appeared in O, the Oprah Magazine over its fifteen year history.