Mellikon has a population (as of December 2018) of 224  As of 2008, 44.4% of the population are foreign nationals.
 Over the last 10 years (1997–2007) the population has changed at a rate of -6.7%.
 Most of the population (as of 2000) speaks German(93.0%), with Portuguese being second most common ( 3.1%) and Dutch being third ( 1.2%).

As of 2008, the gender distribution of the population was 49.4% male and 50.6% female.
 The population was made up of 108 Swiss men (43.7% of the population), and 14 (5.7%) non-Swiss men.
 There were 112 Swiss women (45.3%), and 13 (5.3%) non-Swiss women.
 In 2008 there were 2 live births to Swiss citizens and 1 death.
 Ignoring immigration and emigration, the population of Swiss citizens increased by 1 while the foreign population remained the same.
 There were 1 Swiss man who immigrated from another country back to Switzerland.
 The total Swiss population change in 2008 was a decrease of 6 and the non-Swiss population change was an increase of 4 people.
 This represents a population growth rate of -0.8%.

The age distribution, as of 2008, in Mellikon is; 22 children or 8.8% of the population are between 0 and 9 years old and 39 teenagers or 15.5% are between 10 and 19.
 Of the adult population, 21 people or 8.4% of the population are between 20 and 29 years old.
 18 people or 7.2% are between 30 and 39, 46 people or 18.3% are between 40 and 49, and 49 people or 19.5% are between 50 and 59.
 The senior population distribution is 28 people or 11.2% of the population are between 60 and 69 years old, 12 people or 4.8% are between 70 and 79, there are 15 people or 6.0% who are between 80 and 89,and there is 1 person who is between 90 and older.

As of 2000 the average number of residents per living room was 0.54 which is about equal to the cantonal average of 0.57 per room.
 In this case, a room is defined as space of a housing unit of at least 4 m² (43 sq ft) as normal bedrooms, dining rooms, living rooms, kitchens and habitable cellars and attics.
 About 71.1% of the total households were owner occupied, or in other words did not pay rent (though they may have a mortgage or a rent-to-own agreement).

As of 2000, there were 3 homes with 1 or 2 persons in the household, 26 homes with 3 or 4 persons in the household, and 61 homes with 5 or more persons in the household.
 As of 2000, there were 96 private households (homes and apartments) in the municipality, and an average of 2.6 persons per household.
 In 2008 there were 65 single family homes (or 67.0% of the total) out of a total of 97 homes and apartments.
 There were a total of 5 empty apartments for a 5.2% vacancy rate.
 As of 2007, the construction rate of new housing units was 0 new units per 1000 residents.

In the 2007 federal election the most popular party was the SVP which received 32.55% of the vote.
 The next three most popular parties were the Green Party (19.44%), the SP (16.88%) and the CVP (16.5%).
 In the federal election, a total of 94 votes were cast, and the voter turnout was 50.8%.

The historical population is given in the following table:
Mellikon has a population (as of December 2018) of 224  As of 2008, 44.4% of the population are foreign nationals.  Over the last 10 years (1997–2007) the population has changed at a rate of -6.7%.  Most of the population (as of 2000) speaks German(93.0%), with Portuguese being second most common ( 3.1%) and Dutch being third ( 1.2%).
As of 2008, the gender distribution of the population was 49.4% male and 50.6% female.  The population was made up of 108 Swiss men (43.7% of the population), and 14 (5.7%) non-Swiss men.  There were 112 Swiss women (45.3%), and 13 (5.3%) non-Swiss women.  In 2008 there were 2 live births to Swiss citizens and 1 death.  Ignoring immigration and emigration, the population of Swiss citizens increased by 1 while the foreign population remained the same.  There were 1 Swiss man who immigrated from another country back to Switzerland.  The total Swiss population change in 2008 was a decrease of 6 and the non-Swiss population change was an increase of 4 people.  This represents a population growth rate of -0.8%.
The age distribution, as of 2008, in Mellikon is; 22 children or 8.8% of the population are between 0 and 9 years old and 39 teenagers or 15.5% are between 10 and 19.  Of the adult population, 21 people or 8.4% of the population are between 20 and 29 years old.  18 people or 7.2% are between 30 and 39, 46 people or 18.3% are between 40 and 49, and 49 people or 19.5% are between 50 and 59.  The senior population distribution is 28 people or 11.2% of the population are between 60 and 69 years old, 12 people or 4.8% are between 70 and 79, there are 15 people or 6.0% who are between 80 and 89,and there is 1 person who is between 90 and older.
As of 2000 the average number of residents per living room was 0.54 which is about equal to the cantonal average of 0.57 per room.  In this case, a room is defined as space of a housing unit of at least 4 m² (43 sq ft) as normal bedrooms, dining rooms, living rooms, kitchens and habitable cellars and attics.  About 71.1% of the total households were owner occupied, or in other words did not pay rent (though they may have a mortgage or a rent-to-own agreement).
As of 2000, there were 3 homes with 1 or 2 persons in the household, 26 homes with 3 or 4 persons in the household, and 61 homes with 5 or more persons in the household.  As of 2000, there were 96 private households (homes and apartments) in the municipality, and an average of 2.6 persons per household.  In 2008 there were 65 single family homes (or 67.0% of the total) out of a total of 97 homes and apartments.  There were a total of 5 empty apartments for a 5.2% vacancy rate.  As of 2007, the construction rate of new housing units was 0 new units per 1000 residents.
In the 2007 federal election the most popular party was the SVP which received 32.55% of the vote.  The next three most popular parties were the Green Party (19.44%), the SP (16.88%) and the CVP (16.5%).  In the federal election, a total of 94 votes were cast, and the voter turnout was 50.8%.
The historical population is given in the following table:
Mellikon