Sickle cell disease and beta-thalassemia are two genetic disorders that are caused by a slip in the genes for hemoglobin. The study aims to assess the level of knowledge and awareness of beta-thalassemia and sickle cell disease among single adults and married with no children. This is a cross-sectional study design, targeting males and females who live in the Kingdom of Saudi Arabia. The sample size was estimated by using the sample size formula. A sample size of 384 was determined with a 95% confidence level. Also, Microsoft Office Excel (2016) was used to enter the data into the computer, then imported into the SPSS version 20 application to perform statistical analysis. The study included 744 participants, 55.1% of them were females and 44.1% of them were males. 64.2% of participants aged between 18- 25 years old. Only 4.7% of participants had good knowledge of SCD, 41.7% had moderate knowledge and 53.6% had poor knowledge. The level of knowledge of thalassemia was found to be good in only 45 (6%) of participants, 34% had moderate knowledge and 60% had poor knowledge. Participants&#39; knowledge scores regarding SCD were not significantly associated with any of their demographic characteristics. However, knowledge of thalassemia was significantly associated with educational level and monthly income (P< 0.05). In conclusion, the current study demonstrates a low knowledge level regarding sickle cell disease and thalassemia among the Saudi general population.