Two field experiments were carried out at the private field in El-Hawawsha Village, Dakahlia Governorate, Egypt, during the two successive summer seasons of 2016 and 2017 to study the effect of irrigation intervals, humic acid application and their interaction on growth and productivity of sweet pepper cv. "California wonder". The experiments were carried out in split-plots design with three replications. The obtained results showed that 15 days irrigation interval significantly increased number of leaves/plant, fresh and dry weight/plant, leaf area/plant, yield/plant, total yield, chlorophylls a, b and total chlorophyll of sweet pepper leaves and vitamin C, total soluble solids (TSS %) and acidity of pepper fruits as compared with irrigation at 20 days, which had the lowest significant values. Soil application of humic acid showed significant increases in all studied parameters as compared with control in both seasons. The superior application was soil application of 3 kg humic acid/fed, followed by soil application of 2 kg humic acid/fed, then foliar application of 2 g humic acid/L and foliar application of 1 g humic acid /L in both seasons. The highest values of all the studied characters were resulted from irrigation sweet pepper plants every 15 days combined with soil application with humic acid at the rate of 3 kg/fed in both seasons. Therefore, this treatment can be concluded under the same conditions.