Presenting 55 Commonwealth Avenue, a rare opportunity to acquire one of Back Bay's finest turnkey single-family homes, an address that rarely, if ever, comes to market. Spanning nearly 11,000 SF on the sunny side, this exceptional home offers a combination of scale, natural light, and turnkey living. Designed for both entertaining and everyday living, the home features formal living and dining rooms, an expansive family room, chef's kitchen, library, multiple offices,media room, catering kitchen, and a wellness level with fitness studio, and sauna. The residence offers 5+ bedrooms with multiple ensuite baths, three private terraces, nine fireplaces, temperature-controlled wine room, multiple laundry rooms, and a best-in-class elevator with access to every level. Complete with 2 private garage spaces and 1 gated outdoor space, this home stands as the only turnkey single-family residence available on the sunny side of the second block of Comm Ave, a genuine once-in-a-generation offering.