The 2010 United States Census[REF] reported that Fillmore had a population of 15,002.
The population was spread out with 4,534 people (30.2%) under the age of 18, 1,555 people (10.4%) aged 18 to 24, 4,141 people (27.6%) aged 25 to 44, 3,221 people (21.5%) aged 45 to 64, and 1,551 people (10.3%) who were 65 years of age or older.