The Williams Block is a historic commercial building at 183-187 Water Street in downtown Augusta, Maine.

Built in 1862, it is the only remaining building south of Bridge Street to survive a devastating 1865 fire, and one of a small number of surviving commercial buildings (of many) designed by Francis H. Fassett.

It is a three-story brick building, six bays wide, with a flat roof and projecting cornice.

The windows are set in rounded-arch openings, with keystoned molded hoods, and bracketed lintels that are joined together within each group.

Although Fassett designed many buildings in Augusta, many of the commercial ones were destroyed in the 1865 fire, and this is the only one to survive.