European settlement began in the mid 19th century supported by railway construction in 1856. At the turn of the century the area had a population of 2,500 people and with fertile soils, produced crops for distribution in Sydney.
Rapid population increase after World War II saw the settlement of many ex-service men and European migrants. Large scale Housing Commission development in the 1950s swelled the population to 38,000. By 1979, the population had reached 120,000 and the City was becoming one of the larger Local Government Areas in NSW.
On 4 September 2006, Fairfield Council announced that it had banned spitting in public, which is now punishable with a fine of up to $1100. This is the only ruling of its kind in New South Wales. This also applies to people who spit their chewing gum onto the floor.
A large portion of Fairfield's residents are migrants and their descendants. Originally, most of the migrants were Italian or from the former Yugoslavia. Later arrivals were from Vietnam which sparked the crime gang 5T, then came migrants from Cambodia and Laos, followed by Assyrian, Lebanese and Latino populations. In recent years, an influx of African people has begun in the area. Fairfield is considered one of the most ethnically diverse suburbs in the entire world.
Large Assyrian,Filipino, African, Italian and Spanish-speaking populations reside in Fairfield and surrounding suburbs such as Bossley Park, Wetherill Park and Smithfield.
While Fairfield City has a comparatively young population with many young families, the greatest growth is occurring in the number of older residents, those aged 65 years or more.
Large expanses of rural land characterise the suburbs of Horsley Park and Cecil Park. There are 580 parks (60 of which are major parks) and the new Western Sydney Regional Parklands.
Eight creeks, 80 kilometres in length, have their headwaters in Fairfield City and flow into the Georges River and Hawkesbury Nepean catchments. The impact of development over the past 50 years has resulted in severe degradation of the natural habitat in the creek banks and water quality has been assessed as very poor in recent years. Strategies are being implemented so that this trend is being reversed.
Air quality in the City is heavily impacted upon by an insufficiently integrated public transport system, creating an over reliance upon private vehicles for moving people and freight.
There are about 17 schools in the City of Fairfield. There are many successful Public Schools in the Fairfield region: Fairfield Public School, Fairfield High School, St Johns Park High School, Westfields Sports High School, Fairvale High School, Yennora Public School, Canley Vale High School and many more. There are also many Catholic Schools such as: Patrician Brothers' College, Our Lady of the Rosary Primary School, Mary Mackillop College and Freeman Catholic College. Patrician Brothers' Primary School was also previously located in Fairfield and now closed down as of 2007.