Background Due to the change in screen time usage in the last decade, there is needed to add more evidence about the relationship of screen time and sleep duration. Objective To assess the association between screen time and sleep duration among Spanish children between 1 and 14 years old. Methods We used data from the 2017 Spanish National Health survey, conducted on a representative sample of the Spanish population. We categorised daily leisure screen time as 0‐59, 60‐119, 120‐179, and ≥180 minutes. We classified sleep duration, depending on the age, as proper sleep duration and short sleep duration. We calculated unadjusted, and adjusted prevalence ratio (PR) and 95% confidence interval (CI) of short sleep duration according to daily leisure screen time after adjusting for potential confounders. PR’s were derived from fitting generalised linear models with Poisson distribution and robust variance. Results Of the 5517 Spanish children aged 1‐14 years, 44.3% spent 120 minutes or more of daily leisure screen time and 23.6% had short sleep duration. 24.5% and 28.2% of children spending between 120 and 179 minutes and exceeding 180 minutes of daily leisure screen time suffered short sleep duration, respectively. In the adjusted model, higher patterns of daily leisure screen time were associated with short sleep duration: adjusted PR120‐179 = 1.34 (95% CI 1.18, 1.54) and adjusted PR≥180 = 1.48 (95% CI 1.27, 1.73). Conclusions Around one out of four Spanish children between 1 and 14 years old, exceeding 120 minutes of daily leisure screen time, had short sleep duration. More scientific research is needed for institutions to work on providing novel healthcare programmes that consider these new determinants of child health.