The population of Marlin City is comprised of a range of demographics, including those of children, the elderly, and those with special needs. There are about 73,339 people living in the city, and just over 72,000 are institutionalized. However, the city is also diverse in terms of its ethnic composition. Approximately 1.1% of the population speaks Urdu at home. It is also the second-most populous city in the state.
In 2010, there were 1,197 households, of which 380 were families. Among these, 380 were households with children under the age of 18. Two hundred and seventy-seven were opposite-sex married couples. Another hundred and fifty-seven were households with a female householder without her husband, while 57 were opposite-sex partnerships. Twenty-one were single-person households and 94 were senior citizens living alone. The average household size was two and a half people.