Deer Island is an unincorporated community and census-designated place in Columbia County, Oregon, United States. As of the 2010 census it had a population of 294.

The community is located along U.S. Route 30 north-northwest of Columbia City. Deer Island has a post office with ZIP code 97054.

Historical population

Census	Pop.	Note	%±
2010	294		—
2020	323		9.9%
U.S. Decennial Census

As of the 2020 census, there were 323 people, 143 housing units, and 93 families in the CDP. In Deer Island there were, 282 White people, 0 African Americans, 10 Native Americans, 2 Asians, 0 Pacific Islanders, 6 people that were from some other race, and 23 from two or more races. 30 people were from Hispanic or Latino origin.

The ancestry of Deer Island is 21.8% German, 13.8% Irish, 11.5% French, 2.9% Italian, and 2.9% Norwegian.

The median age in Deer Island was 52.4 years old. 29.3% of the population were over 65, with 22.4% from 65 to 74, and 6.9% from 75 to 84. 0.0% of the population were foreign born.

The median household income was $23,750, with families having $37,500, and non-families having $18,750. 5.2% of the population were in poverty, and 9.9% of people 18 to 64 were in poverty.