Coronavirus disease-19 (COVID-19) is a highly contagious infection that mainly affects the respiratory system of patients. To date, more than 10 million people have been affected by this virus, and Saudi Arabia has also reported over 210 million cases. At present, there is no established treatment for COVID-19. Vaccination is one of the ways to defeat the pandemic. Recent reports have indicated rare but serious adverse events after vaccination, causing an anxious response from the general public worldwide. Therefore, this study was aimed at evaluating the knowledge, attitude, and perception of the COVID-19 vaccine among the Saudi population. This study is a cross-sectional, web-based online survey conducted using a snowball sampling technique. A self-administered questionnaire prepared in Arabic and English was used to collect feedback from the general population on their knowledge, attitudes, and perceptions about the COVID-19 vaccine. Participants (n = 2022) from different regions of the country replied to the questions. The responses to the questions were recorded on a spreadsheet and analyzed using the SPSS software. Statistical analysis was performed using one-way ANOVA and non-parametric tests to draw conclusions about the results. Multivariate stepwise regression analysis was performed to determine the association between the knowledge, attitude, and perception scores and the demographic variables. p < 0.05 was used to indicate the significance of the data. The data from the study indicated that most of the participants were males (81%), between 18 and 59 years of age (85.9%), Saudi nationals (98.3%), and possessed graduation or above as a qualification (62.9%). The results suggest that a major portion of respondents have satisfactory knowledge (76%), a positive attitude (72.4%), and perception (71.3%) towards the use of COVID-19 vaccines. Their responses can be categorized as between ‘good’ and ‘fair’. However, 30–40% of respondents lacked information about COVID-19 vaccination availability for under 18-year-olds as well as for pregnant women, in addition to the lack of knowledge about the serious unreported adverse reactions and long-term protection offered by the vaccine against coronavirus. The correlation analysis between the variables (p > 0.05) indicated that the response to the KAP domains has no direct relationship. The survey results suggest that most of the Saudi population has sound knowledge and a positive attitude and perception. Since the COVID-19 vaccines have been approved for use in pregnancy and above 12-year-old children by health authorities, the lack of information shown by a significant percentage of participants requires strategies to update this information. Awareness programs targeting all sections of the population must be continued to provide all the updates, including vaccinations for pregnant women and children.