Obersiggenthal has a population (as of ) of . , 32.1% of the population was made up of foreign nationals. Over the last 10 years the population has grown at a rate of 6.8%. Most of the population () speaks German (80.7%), with Serbo-Croatian being second most common ( 4.8%) and Italian being third ( 2.6%). The age distribution, , in Obersiggenthal is; 782 children or 9.6% of the population are between 0 and 9 years old and 883 teenagers or 10.8% are between 10 and 19. Of the adult population, 944 people or 11.5% of the population are between 20 and 29 years old. 1,182 people or 14.5% are between 30 and 39, 1,349 people or 16.5% are between 40 and 49, and 1,010 people or 12.4% are between 50 and 59. The senior population distribution is 977 people or 12.0% of the population are between 60 and 69 years old, 660 people or 8.1% are between 70 and 79, there are 337 people or 4.1% who are between 80 and 89, and there are 50 people or 0.6% who are 90 and older. , there were 508 homes with 1 or 2 persons in the household, 1,733 homes with 3 or 4 persons in the household, and 976 homes with 5 or more persons in the household. The average number of people per household was 2.26 individuals. In the
2007 federal election the most popular party was the
SVP which received 29.6% of the vote. The next three most popular parties were the
SP (19.3%), the
CVP (18.9%) and the
FDP (15.1%). ==Heritage sites of national significance==