ObjectiveTo examine the relationship between the diet quality of children aged 2–5 years cared for in family child care homes (FCCHs) with provider adherence to nutrition best practices. DesignCross-sectional analysis. ParticipantsFamily child care home providers (n = 120, 100% female, 67.5% Latinx) and children (n = 370, 51% female, 58% Latinx) enrolled in a cluster-randomized trial. Main Outcome MeasuresData were collected over 2 days at each FCCH. The Environment and Policy Assessment and Observation tool was used to document whether providers exhibited nutrition practices on the basis of the Nutrition and Physical Activity Self-Assessment for Child Care. Each practice was scored as either present or absent. Children's food intake was observed using Diet Observation at Child Care and analyzed with the Healthy Eating Index–2015. AnalysisMultilevel linear regression models assessed the association between providers exhibiting best practices regarding nutrition and children's diet quality. The model accounted for clustering by FCCH and controlled for provider ethnicity, income level, and multiple comparisons. ResultsChildren in FCCHs in which more of the best practices were implemented had higher diet quality (B = 1.05; 95% confidence interval [CI], 0.12–1.99; P = 0.03). Specifically, children whose providers promoted autonomous feeding (B = 27.52; 95% CI, 21.02–34.02; P < 0.001) and provided nutrition education (B = 7.76; 95% CI, 3.29–12.23; P = 0.001) had higher total Healthy Eating Index scores. Conclusions and ImplicationsFuture interventions and policies could support FCCH providers in implementing important practices such as autonomy feeding practices, talking informally to children about nutrition, and providing healthful foods and beverages.