Waltham   -  Watertown   - Wellesley - Westborough -  Weston  - Westwood - Woburn - Woods-hole - Worcester - About Arlington Arlington is a  town  in  Middlesex County ,  Massachusetts ,  United States , six miles (10 km) northwest of  Boston . The population was 42,844 at the 2010 census. Article Source :  http://en.wikipedia.org/wiki/Arlington,_Massachusetts