Higher consumption of “ultra-processed”(UP) foods has been linked to adverse health outcomes. The present paper aims to characterize percent energy from UP foods by participant socio-economic status (SES), diet quality measures, self-reported food expenditure, and energy-adjusted diet cost. Participants in the population-based Seattle Obesity Study III (n=755) conducted in WA in 2016-17 completed socio-demographic and food expenditure surveys and the Food Frequency Questionnaire (FFQ). Education and residential property values were measures of SES. Retail prices of FFQ component foods (n=378) were used to estimate individual-level diet cost. Healthy Eating Index (HEI-2015) and Nutrient Rich Food Index (NRF9.3) were measures of diet quality. UP foods were identified following NOVA classification. Multivariable linear regressions were used to test associations between UP foods energy, socio-demographics, two estimates of food spending, and diet quality measures. Higher percent energy from UP foods was associated with higher dietary energy density, and lower HEI-2015 and NRF9.3 scores. The bottom decile of diet cost ($216.4/mo) was associated with 67.5% energy from UP foods; the top decile ($369.9/mo) was associated with only 48.7% energy from UP foods. Percent energy from UP foods was inversely linked to lower food expenditures and diet cost. In multivariate analysis, percent energy from UP foods was predicted by lower food expenditures, diet cost, and education, adjusting for covariates. Percent energy from UP foods was linked to lower food spending and lower SES. Efforts to reduce UP foods consumption, an increasingly common policy measure, need to take affordability, food expenditures and diet costs into account.