According to the 2001 Census, the population of Kottayam district stood at 19,74,551, which constituted 5.6% of the total population of Kerala. The density for the district was calculated to be 896 persons per square kilometre, whereas the municipal region of Kottayam reflected a much higher density of 3,905 persons per square kilometre. This indicates a strong concentration of population in the urban core of the municipality.

In absolute terms, Kottayam Municipality had a population of 97,174 in 1971, which saw slight growth over the decades, reaching 1,02,726 by 2001. Notably, the growth rate has fluctuated, and some areas within the municipality have even shown negative trends in population growth, especially in the older municipal limits. Comparatively. nearby panchayats such as Panachikkad, Vijayapuram, and Kumaranalloor have shown a consistent rise in population, suggesting a clear pattern of outward migration and peripheral expansion