According to the 2000 U.S. Census the population of La Conner was 761. Between 1990 and 2000, U.S. Census data reports that the population of La Conner increased by 16%. In 2000 the percentage of males and females was 45.2% and 54.8% respectively. The racial composition of the population in 2000 was predominantly White (90.8%), followed by American Indian and Alaska Native (1.7%), Black or African American (0.8%), and Asian (0.3%). There were zero Pacific Islanders living in La Conner in 2000. Few individuals (3.8%) classified themselves as belonging to some other race. Overall, 2.6% of the population identified themselves as belonging to two or more races. Slightly over five percent of the population (6.2%) identified themselves as Hispanic or Latino.

In 2000 the median age of the population was 45.5, which was higher than the national median of 35.3 for the same year. According to the 2000 U.S. Census the population of La Conner had an even age distribution; approximately 51.1% of the population was between the ages of 21 and 59. A small percentage (5.9%) of the population was foreign-born; of the foreign-born population 60.9% were born in Canada. Approximately 73.9% of the population of La Conner in 2000 was living in family households. The 2000 U. S. Census reports that 91.2% of the population over 18 years of age had received a high school degree or higher, 33.3% had received a Bachelor’s degree or higher, and 11.4% received a graduate or professional degree; as compared to the national averages of 79.7%, 22.3%, and 7.8% respectively.

There were 372 households out of which 21.8% had children under the age of 12 living with them, 43.8% were married couples living together, and 6.7% had a female householder with no husband present. 41.7% of all households were made up of individuals and 22.0% had someone living alone who was 65 years of age or older. The average household size was 2.05 and the average family size was 2.79.

The median income for a household in the town was $42,344, and the median income for a family was $52,083. Males had a median income of $40,074 versus $26,875 for females. The per capita income for the town was $24,308. About 8.8% of families and 11.8% of the population were below the poverty line, including 20.3% of those under age 18 and 8.1% of those age 65 or over.