This wacky, one-of-a-kind festival honors the invention of Marshmallow Fluff by Archibald Query in Somerville in 1917 and salutes the spirit of innovation that still thrives in Union Square today. Now in its 21st year, the What the Fluff? Festival showcases clever culinary creations, live music and entertainment, and incredible artistic innovations brought to life by more than 100 local businesses and participating vendors.

Raise a glass to Union Square as What the Fluff? turns 21! This year’s theme – Legally Fluff: A Toast to Union Square – is an ode to 21 years of fluff-filled fun for all ages. Put on the party hats, blow up the balloons, grab a bubbly bev, and celebrate Somerville’s signature sweet spread in style. Prost! Sláinte! ¡Salud! Here’s to Union Square!

What the Fluff? is brought to you by Union Square Main Streets with a mission to preserve the unique character and advance the strength of the Union Square business district and community in partnership with the Somerville Arts and Culture.

Please stay tuned for event details, location updates and more!

Severe weather and other emergencies can happen. Fluff Festival attendees can sign up for day-of emergency text alerts for this year’s event: text FLUFF26 to 888777.

Accessibility Needs:

Persons with disabilities who need auxiliary aids and services for effective communication (i.e., CART, ASL), written materials in alternative formats, or reasonable modifications in policies and procedures in order to access the programs, activities, and meetings of the City of Somerville should contact the ADA Coordinator in advance at 617-625-6600 x 2059 [email protected].

The City of Somerville can provide you with an interpreter in your language for free. To request an interpreter, please contact us at [email protected] or call 311 (617-666-3311) at least 7 days in advance of this event.