An experiment was conducted during the winter season of 2020-2021 in the fields of a farmer in the city of Ramadi - Anbar province - Iraq, according to the randomized complete block design [RCBD] with split-plot arrangement and three replications. The study examined the effect of four seed rates [100, 130, 160, and 190 kg ha-1] on the growth and yield of four barley varieties [IPA256, Amal, Buhooth 22, and Baraq]. Seed rates allocated to the main plot, while the varieties allocated to the sub-plots. The results showed that the seed rate of 100 kg ha-1 gave the highest mean leaf area of 14.52 cm2 and the highest 1000-grain weight of 46.88 g. However, the seed rate of 190 kg ha-1 outperformed in crop growth rate, biological yield, grain yield, and harvest index, with 14.19 g m-2 day-1, 20.50 ton ha-1, 5.59 ton ha-1, and 27.40%, respectively. The varieties differed significantly in most of the studied traits, with the variety Buhooth 22 outperformed with the highest mean leaf area and biological yield of 13.05 cm2 and 20.69 ton ha-1, respectively. However, the variety IPA256 gave the highest mean crop growth rate, yield per unit area, and harvest index of 14.38 g m-2 day-1, 5.77 ton ha-1, and 32.23%, respectively. The interaction between varieties and seed rates showed that the variety IPA256 with the seed rate of 190 kg ha-1 gave the highest yield per unit area of 6.17 ton ha-1.