In the 2015 census, the population of Tarlac City was 342,493 people, with a density of 1,200 inhabitants per square kilometer or 3,100 inhabitants per square mile.

According to statistics compiled by the Philippine Government, the most dominant religion in the City is Christianity with 73% of the population adhering to the faith. The majority of Christians are Roman Catholics followed by a large concentration of Iglesia ni Cristo ( Church of Christ). Other Christian groups belong to various Protestants denominations. The remaining 27% belong to non-Christian religious such as Islam, etc.

Based on the 1995 census conducted by the NSO within the City of Tarlac, there are three major dialects generally spoken by the people. namely; Pampango, Tagalog and Ilocano. Pampango or Kapampangan represent 75.22% tagalog 14.58%, Ilocano 8.55%, and the remaining 1.65% constitute other dialects such as Pangasinense, Visayan, Bicolano, etc.

The October 2000 survey conducted by the NSO within the City of Tarlac states that out of the 164,00 household population aged 15 years old and above, 60.37% are in the labor force, while 39.63% are not. Out of those in the labor force, 54.88% are employed, 5.49% are unemployed, having a 90.50% employment rate and 9.50% unemployment with a visible underemployment rate of 0.70 %. Fifty percent (50%) of the 90,000 household populations are mostly employed in the service industry, while 34.44% are in various industries and 15.56% are in the agricultural industry.