This study explored associations between free sugars intake (using non-milk extrinsic sugars as proxy) and nutrient intakes among children aged 1·5–18 years in the UK National Diet and Nutrition Survey 2008–2012. Dietary records were completed by 2073 children (95 % completed 4 d). Mean free sugars intakes (% energy) were 11·8, 14·7 and 15·4 % in the 1·5–3, 4–10 and 11–18 years age groups, respectively. Nutrient intakes and nutrient density were compared across quintiles (Q1–Q5) of free sugars intake (% energy) within each age group. Energy intake rose from Q1 to Q5 of free sugars, whereas percentages of energy intake from fat, SFA and protein dropped. Associations with micronutrients (mg/d or mcg/d) were mostly non-significant, but among 11–18-year-olds there were significant negative associations with Zn, Se, Fe, Cu, and vitamin A and D. There were stronger negative associations with micronutrient density (mg/mcg per 4·18 MJ) for most nutrients in all age groups. Associations with vitamin C were positive. Results were similar after excluding misreporters. Children aged 4–18 years who consumed average amounts of free sugars or above (>13 % energy or Q3–Q5) had lower diet quality than those consuming <10 % free sugars (Q1), but there were insufficient data to assess diets with 5 % free sugars. High consumers obtained a higher proportion of free sugars from soft drinks, fruit juice and sugar confectionery and less from breakfast cereals. Ultimately, nutrient intakes depend on the total dietary pattern; however, reducing overconsumption of sugary foods and drinks with low nutrient density may help improve diet quality.