Dietary patterns analyse combinations of foods eaten. This cross-sectional study identified dietary patterns and their nutrients. Associations between dietary patterns and socio-demographic and lifestyle factors were examined in older New Zealand adults. Dietary data (109-item food frequency questionnaire) from the Researching Eating, Activity and Cognitive Health (REACH) study (n = 367, 36% male, mean age = 70 years) were collapsed into 57 food groups. Using principal component analysis, three dietary patterns explained 18% of the variation in diet. Dietary pattern associations with sex, age, employment, living situation, education, deprivation score, physical activity, alcohol, and smoking, along with energy-adjusted nutrient intakes, were investigated using regression analysis. Higher ‘Mediterranean’ dietary pattern scores were associated with being female, higher physical activity, and higher education (p < 0.001, R2 = 0.07). Higher ‘Western’ pattern scores were associated with being male, higher alcohol intake, living with others, and secondary education (p < 0.001, R2 = 0.16). Higher ‘prudent’ pattern scores were associated with higher physical activity and lower alcohol intake (p < 0.001, R2 = 0.15). There were positive associations between beta-carotene equivalents, vitamin E, and folate and ‘Mediterranean’ dietary pattern scores (p < 0.0001, R2 ≥ 0.26); energy intake and ‘Western’ scores (p < 0.0001, R2 = 0.43); and fibre and carbohydrate and ‘prudent’ scores (p < 0.0001, R2 ≥ 0.25). Socio-demographic and lifestyle factors were associated with dietary patterns. Understanding relationships between these characteristics and dietary patterns can assist in health promotion.