This study explores students' acceptance and use of ChatGPT in Saudi Arabian higher education. A survey of 520 students from a public university in Saudi Arabia was conducted using the Unified Theory of Acceptance and Use of Technology (UTAUT2) framework. The findings showed that performance expectancy (PE), social influence (SI), and effort expectancy (EE) significantly influenced behavioral intention (BI) to use ChatGPT, while facilitating conditions (FCs) did not have a significant direct effect on BI or actual use. However, BI partially mediated the relationship between PE, SI, and FC with actual ChatGPT use, and fully mediated the relationship between EE and actual use. The study highlights the importance of social influence in driving students' acceptance of ChatGPT, as students are influenced by peers and colleagues. PE was the second most important factor, indicating that students perceive ChatGPT as a valuable tool for academic purposes. EE was the third most important factor, showing that students find ChatGPT easy to use and understand. FCs had a negative impact on BI, likely due to a lack of resources and support. The study also found that BI significantly influenced actual ChatGPT use. These findings have implications for higher education institutions in Saudi Arabia, emphasizing the need for adequate resources and support to ensure responsible and ethical use of AI tools like ChatGPT. The study also highlights the importance of addressing ethical concerns related to AI use in education.This study explores students' acceptance and use of ChatGPT in Saudi Arabian higher education. A survey of 520 students from a public university in Saudi Arabia was conducted using the Unified Theory of Acceptance and Use of Technology (UTAUT2) framework. The findings showed that performance expectancy (PE), social influence (SI), and effort expectancy (EE) significantly influenced behavioral intention (BI) to use ChatGPT, while facilitating conditions (FCs) did not have a significant direct effect on BI or actual use. However, BI partially mediated the relationship between PE, SI, and FC with actual ChatGPT use, and fully mediated the relationship between EE and actual use. The study highlights the importance of social influence in driving students' acceptance of ChatGPT, as students are influenced by peers and colleagues. PE was the second most important factor, indicating that students perceive ChatGPT as a valuable tool for academic purposes. EE was the third most important factor, showing that students find ChatGPT easy to use and understand. FCs had a negative impact on BI, likely due to a lack of resources and support. The study also found that BI significantly influenced actual ChatGPT use. These findings have implications for higher education institutions in Saudi Arabia, emphasizing the need for adequate resources and support to ensure responsible and ethical use of AI tools like ChatGPT. The study also highlights the importance of addressing ethical concerns related to AI use in education.