Sonoma Plaza, Historic district and square in Sonoma, United States.

Sonoma Plaza is a historic district and National Historic Landmark at the center of Sonoma, featuring buildings in the Italianate and Spanish Colonial styles. The large square is framed by streets on all sides and filled with lawns, trees, and walkways surrounded by shops, restaurants, and public facilities.

Sonoma Plaza was laid out in 1835 by Mariano Guadalupe Vallejo, the founder of Sonoma. The Bear Flag Revolt took place on its grounds in 1846, leading to the short-lived Republic of California. Sonoma City Hall, at the plaza's center, was dedicated in 1908.

Wine tasting rooms and art galleries line the square, where visitors can sample local wines and regional products. The mix of shops and restaurants around the plaza shows how closely the town is tied to the farming tradition of the Sonoma Valley.

Several parking areas surround the plaza, and the square itself is easy to walk through in any direction. Visiting on a weekday generally means fewer crowds, making it easier to move around the shops and historic buildings along the edges.

Sonoma City Hall, at the plaza's center, was built with four identical sides so that no merchant on any side of the square would be favored. The building was dedicated in 1908 and is still in use. The site of the original Bear Flag raising went unmarked for years until the Native Sons of the Golden West raised $500 and the legislature appropriated $5,000 for a monument.