Six divergent sunflower genotypes were coupled using a half-diallel mating design to determine types of combining abilities, and heterosis under normal irrigation and water stress conditions for earliness and maturity traits as well as growth traits, in Kafr–El–Mayasra Village, EL-Zarqa Distrect, Damietta Governorate, Egypt during the summer seasons 2019 and 2020. The parents and their F₁ crosses were evaluated using a design of randomized complete blocks with 3 replicates. The GCA/SCA ratio under normal irrigation and water stress conditions revealed a predominance of non-additive gene action for earliness and maturity traits as well as growth traits.  For days to full maturity, Sakha 53 at normal-watering and L-105 at moisture-stress conditions, and L-216 under normal-watering and L-105 under moisture-stress conditions for no. of green leaves were the best general combiners. The generated combinations Sakha 53 × L-105 for days to full maturity, L-10 × L-216 for no. of green leaves plant^-1, and L-8 × Sakha 53 for stem diameter under both irrigation treatments had desirable SCA effects as well as mid and better parents heterosis.