Purpose <p>Studies examining the concordance of the dietary intake of mothers and their weaning children across the food groups are scarce. This study aimed to develop culturally relevant, healthy eating indices to examine the diet quality of mother–child dyads in Singapore.</p> Methods <p>488 pairs of mothers with children aged 6–24 months were recruited between August 2017 and December 2018 in this cross-sectional study. Their food frequency questionnaire data were collected for comparison to the national dietary guidelines. ANOVA tests were performed on the diet quality scores of mother–child dyads and comparisons between socioeconomic and demographic characteristics were determined by Mann–Whitney tests with <i>post hoc</i> analysis.</p> Results <p>Median diet quality score was 57/100 (48.7–65.9) and 65/100 (56.5–72.3) for mothers and children respectively, with intakes of whole grains, vegetables and fruit failing to meet the recommendations. Mothers’ diet quality tended to less frequently align with recommendations than that of the children. The median component score for whole grain was the lowest in mothers and children. Highly educated mothers had higher HEI-SG scores (<i>p</i> = 0.022), and significantly higher scores for whole grains (<i>p</i> = 0.007), vegetables (<i>p</i> = 0.028) and fruit (<i>p</i> &lt; 0.001). Children of Chinese descent had higher overall HEI-SG scores than those of non-Chinese ethnicity.</p> Conclusions <p>The results highlight common limitations in the dietary habits of Singaporean mothers and their children, which may be used to target the development of future national dietary guidelines.</p>