With the spread of synchronous and asynchronous online teaching tools, it has become necessary to identify factors and challenges influencing faculty member adoption of online teaching into teaching practice at Saudi universities. The parallel convergent mixed method was used as the methodology for this study and was conducted in three Saudi universities; Imam Abdulrahman bin Faisal University, King Faisal University, and University of Bisha. The total number of responses from the study instrument was about 124; Imam Abdulrahman bin Faisal University 49, King Faisal University 41, and the University of Bisha 34. The theoretical framework for this study was the Decomposed Theory of Planned Behavior (DTPB) modal. The collection of quantitative and qualitative data as convergent parallel mixed methods was in one phase and concurrently included close-ended and open-ended questions. The data were separately analyzed quantitative and qualitative. The questionnaire instrument was constructed in four parts: (1) faculty demographic information, (2) technologies faculty use most with online teaching, (3) the use of online teaching and learning tools, and (4) utilization of online tools. The first and second sections of the survey instrument were focused on faculty demographics such as gender, age, academic rank, teaching experiences, department or college, nationality, type of contract, and years of experience teaching online courses. Additional information about faculty's most used technologies (such as possession of personal home technology tools, provision of a university office computer, connection to the Internet at a university, and connection to the Internet at home) for online teaching were also collected. Items pertaining to faculty perceptions of challenges associated with using online teaching tools in their teaching practice were also included in the second section of the survey. A 5-point Likert-scale was used for participant responses with 5=Always, 4=Mostly, 3=Moderate, 2=Seldom, and 1=Never. The findings of faculty demographic information and the type of technologies faculty uses most with online teaching that the quantitative findings of the ANOVA for the first part of the analysis, there were no significant differences identified for gender, faculty members' academic rank and experience, nationality, and contract types in relation to the use of university-provided resources for online teaching tools. However, significant differences were found among faculty members based on age, university departments or colleges, and the experience levels of faculty members for using university-provided resources for online teaching tools. In the second part of the ANOVA analysis, which involved comparisons of the variables, there were no significant differences found based on faculty members' age, university, academic rank or experience level, or gender to use a personal digital resource at home. However, the findings from the ANOVA analysis indicated that there were significant differences found for faculty and using personal digital resources. Differences were found between the three different university contract types. Specifically, faculty with non-renewable contracts were found to use personal resources more than those with renewable contracts. Additionally, differences were also found based on nationality, in that Saudi faculty use significantly more personal resources. For the use of online teaching and learning tool's part based on Decomposed Theory of Planned Behavior (DTPB) modal to the attitude, subjective norms, and perceived behavioral control. The attitude findings of the qualitative faculty members indicated that their choices to engage with online teaching tools were greatly influenced by the perceived usefulness of online teaching during COVID-19. This was related to their flexible and interactive nature. Additionally, the quantitative findings showed that the perceived usefulness was significantly impacted by faculty attitudes toward using online tools in their teaching practices. The findings that qualitative findings from this study revealed the individual intentions of faculty in terms of selecting online and digital tools for online instruction that was based on their assessments of expected difficulty toward the outcomes of intended behavior. However, the quantitative findings indicated that peer influence, student influence, and superior influence were significant factors affecting faculty members' subjective norms. Finally, the quantitative findings of perceived behavioral control indicated the significance of facilitating conditions, technology, and resources as factors that affect faculty members' behavioral control over online teaching in this study. The qualitative result indicated that faculty members were engaged in online teaching positively despite the difficulties and challenges and perceived significant usefulness in utilizing various online and digital teaching tools. / Doctor of Philosophy / This descriptive study investigated the factors and challenges influencing faculty member adoption of online teaching into teaching practice at Saudi universities. This study aims to (1) identify whether the differences that exist in Saudi faculty members' use of online tools can be associated with factors such as gender, age, academic rank, teaching experience, department or college, nationality, type of contract, possession of personal online and digital tools at home, provision of a university office with online and digital tools, connection to the Internet at a university, and connection to the Internet at home, (2) determine the perceived advantages and disadvantages for faculty members using online teaching in the instructional process, (3) determine perceived challenges for faculty members using online teaching in the instructional process. The parallel convergent mixed method was used as the methodology for this study and was conducted in three Saudi universities; Imam Abdulrahman bin Faisal University, King Faisal University, and University of Bisha. The total number of responses from the study instrument was about 124; Imam Abdulrahman bin Faisal University 49, King Faisal University 41, and the University of Bisha 34. The theoretical framework for this study was the Decomposed Theory of Planned Behavior (DTPB) modal. The collection of quantitative and qualitative data as convergent parallel mixed methods was in one phase and concurrently included close-ended and open-ended questions. However, both quantitative and qualitative findings indicated that their choices to engage with online teaching tools were greatly influenced by the perceived usefulness of online teaching during COVID-19 and the perceived usefulness was significantly impacted by faculty members' attitudes. The qualitative findings from this study revealed the individual intentions of faculty in terms of selecting online and digital tools for online instruction. This was based on their assessments of expected difficulty toward the outcomes of intended behavior (Yao et al., 2022). For example, faculty members indicated that they used online teaching tools because such tools were easy to operate and provided ample opportunity to interact with several students at the same time. However, faculty members also indicated perceived difficulty and complexity associated with online digital tools. On the other hand, quantitative findings indicated that peer influence, student influence, and superior influence were significant factors affecting faculty members' subjective norms. Finally, the findings from this study indicated that faculty members were engaged in online teaching positively despite the difficulties and challenges. However, they perceived significant usefulness in utilizing various online and digital teaching tools.