- World language collections in Chinese, French, Spanish and Vietnamese
- Library service in Lower Mills was first offered through a branch delivery post in 1875. Full branch services began in 1876 with a dedicated collection and expanded hours.
- In 1883, the branch moved into the vacated Blue Hills Bank building, and in 1936 an addition was opened. The current site of the Lower Mills Branch opened in 1981 on the site of the former Gilbert Stuart School.
- In 2005, the branch underwent renovations, including a new façade and updated heating and cooling systems.