On her weekly podcast, Happier with Gretchen Rubin, she discusses good habits and happiness with her sister Elizabeth Craft, a Los Angeles-based television writer.

She is author of The Happiness Project: Or Why I Spent a Year Trying to Sing in the Morning, Clean My Closets, Fight Right, Read Aristotle, and Generally Have More Fun.

[17] On September 4, 2012, Rubin published the follow-up book Happier at Home: Kiss More, Jump More, Abandon a Project, Read Samuel Johnson, and My Other Experiments in the Practice of Everyday Life.

[28][29] In 2017, Rubin helped create the "Joy Index," a list of the ten "most joyous" places to visit, based on several "happiness factors".

In late 2024, she recommended that people invest in broadening and deepening their relationships, for example by volunteering in the community and inviting acquaintances to meet beyond the usual context.