Letitia Street House, Early Georgian townhouse in West Fairmount Park, Philadelphia, United States.

The Letitia Street House is an early Georgian townhouse built with red brick and featuring symmetrical windows arranged across a two-story facade. Its design reflects colonial building practices with balanced proportions and traditional architectural details common to Philadelphia's early period.

Built about 1713 along the Delaware riverfront, the house was moved to West Fairmount Park in 1883 for Pennsylvania's bicentennial. Long thought to be William Penn's city residence, it was restored in 1931–32 under Fiske Kimball, whose research dated it to after 1703 and before 1715.

The house is named for Letitia Penn (1678–1745), William Penn's daughter, who received the northern half of his reserved city block before 1701 and had it divided into lots; Letitia Street was named for her. From 1932 the Philadelphia Museum of Art ran the house as a small museum of Queen Anne furniture and decorative arts, which closed in 1965.

The building sits within West Fairmount Park and currently serves as office space for a community development organization. Access may be limited during weekdays when the offices are in active use.

For many years the building was mistakenly believed to be William Penn's residence, a confusion that ultimately saved it from demolition and led to its relocation. This misidentification played a role in sparking Philadelphia's early movement to protect historic structures.