Old Greenwich is an area in Fairfield County,Connecticut with a population of 6,819. Old Greenwich, CT Population: 7,000. 87. There are 3,331 male residents living in Old Greenwich and 3,488 female residents. We take you around Old Greenwich to find out what it's like to call it home. View the Old Greenwich, CT population and other interesting demographics including: median age, male to female ratio, marital status, source of income, languages spoken and race breakdown. Overview Livability Real Estate Rentals Demographics. OLD GREENWICH CLEANERS (280 SOUND BEACH AVE in OLD GREENWICH, CT) Small Quantity Generators, between 100 kg and 1000 kg of hazardous waste/month (Resource Conservation and Recovery Act (tracking hazardous waste)) - notification Organizations: RONALD RAINONE (CONTACT/OWNER) OLD GREENWICH TENNIS ACADEMY (151 SOUND BEACH AVENUE in OLD GREENWICH, CT) Demographics. Greenwich Village, CT: Old Greenwich, CT: United States Population: 62,782: 6,860: 321,004,407 Female Population: 52.1%: 51.9%: 50.8% Male Population: 47.9%: 48.1% Key findings. Old Greenwich Connecticut Population Charts According to the most recent demographics data available from the Census Bureau released in December of 2019, Figure 1 Old Greenwich shows it has 6,819 population which is the 4th smallest population of all the other places in the area . Old Greenwich, CT City Data Old Greenwich, CT is a city with great restaurants, attractions, history and people. The total number of households is 2,186 with 3 people per household on average.The median age of the current population is 41 with 3,446 people being married and 1,454 being single. Livability87 AmenitiesA+ Cost of LivingF CrimeA+ EmploymentA+ HousingF SchoolsA+ User RatingsA+. There are around 7,092 people who live in Old Greenwich and approximately 882,567 who live in Fairfield County.