The study aimed to determine the levels of mathematics proficiency among Saudi learners and to compare them with the learners' levels of the first country globally (B-S-J-Z -- China) and regionally (UAE) according to the results of PISA 2018, as well as to identify some of the learners' characteristics that affected their results and their mathematics proficiency levels. The results indicated low levels of mathematics proficiency among Saudi and Emirati learners, who are concentrated at levels 0 and 1, as the levels of mathematics proficiency are very high among Chinese learners, who are concentrated at levels 5 and 6. However, the levels of Emirati learners are slightly higher than Saudi learners, especially at levels 3, 4, and 5. The study also found some characteristics of learners that have the greatest impact on learners' results and levels of mathematics proficiency.