2020 census

As of the 2020 census, there were 53,526 people, 20,984 households in the city.

2010 census

As of the 2010 census, there were 42,393 people, 16,949 households, and 10,869 families residing in the city. The population density was 2,639.7 inhabitants per square mile (1,019.2/km²). There were 18,493 housing units at an average density of 1,151.5 per square mile (444.6/km²). The racial makeup of the city was 74.2% White, 5.4% African American, 1.2% Native American, 8.0% Asian, 1.7% Pacific Islander, 2.6% from other races, and 7.0% from two or more races. Hispanic or Latino of any race were 9.2% of the population.

There were 16,949 households, of which 33.9% had children under the age of 18 living with them, 46.7% were married couples living together, 12.9% had a female householder with no husband present, 4.5% had a male householder with no wife present, and 35.9% were non-families. 28.3% of all households were made up of individuals, and 11% had someone living alone who was 65 years of age or older. The average household size was 2.44 and the average family size was 2.99.

The median age in the city was 34 years. 24.6% of residents were under the age of 18; 10.1% were between the ages of 18 and 24; 29.5% were from 25 to 44; 21.8% were from 45 to 64; and 14.1% were 65 years of age or older. The gender makeup of the city was 47.4% male and 52.6% female.

2000 census

As of 2000 the median income for a household in the city was $46,848, and the median income for a family was $54,923. Males had a median income of $41,053 versus $32,497 for females. The per capita income for the city was $20,224. About 7.1% of families and 8.8% of the population were below the poverty line, including 10.5% of those under age 18 and 5.5% of those age 65 or over.

Neighborhoods

Mushroom Corner is located along Interstate 5 and is included in the Tanglewilde-Thompson Place Census-designated place (CDP) for Census purposes. The "corner" in Mushroom Corner is located at the intersection of Steilacoom Road SE and Marvin Road SE. The community takes its name from the local mushroom crop; the Ostrom Mushroom Farm operated nearby.^{[14][15][16][17]}

Sustainability

Lacey was the twelfth city to be designated an official "Green Power Community" by the U.S. Environmental Protection Agency for its use of renewable energy sources; 8.4% of its total energy use comes from green power sources.^[18] It is working to meet its Alternative Energy Initiative, which includes using 100 percent green electrical energy in all of its municipal buildings, parks, utilities, and 3,000 streetlights and traffic signals; providing electric vehicle charging stations to visitors and employees at its city hall and library campus; and initiating conversion of its municipal fleet to energy efficient vehicles powered by electricity, hybrid technology, and 80/20 biofuel.^[19] Lacey has received the "Tree City, USA" designation from the National Arbor Day Foundation for twenty six years.^[20]

Public secondary schools

• Aspire Middle School (Magnet)
• Chinook Middle School
• Komachin Middle School
• Nisqually Middle School
• Salish Middle School^[22]
• North Thurston High School
• River Ridge High School
• Timberline High School
• South Sound High School (Alternative High School, Closed as of 2021)