This study aims to determine the effect of the Problem Solving learning model on the mathematics learning outcomes of Phase F TITL students at SMKN 5 Padang. This research was motivated by the low mathematics learning outcomes of students, as shown by data from the Mid-Semester Summative Assessment of the Odd Semester of the 2025/2026 Academic Year, indicating that all students in class XI TITL 1 (33 students) had not reached the Minimum Completeness Criteria (KKM), and only 23% of students in class XI TITL 2 achieved mastery. This study used a Quasi-Experimental Research method with a randomized control group only posttest design. The research population consisted of all Phase F TITL students at SMKN 5 Padang, with a sample consisting of two classes selected randomly. The experimental class received treatment using the Problem Solving learning model, while the control class received conventional learning. The research instrument was a mathematics learning outcome test in essay form, which had been tested for validity, reliability, level of difficulty, and discriminating power. The data were analyzed through a normality test (Liliefors), a homogeneity test (F test), and a hypothesis test (one-tailed t-test). Based on the research conducted in Phase F of the TITL major at SMK Negeri 5 Padang, a hypothesis test was carried out using the t-test because the data were normally distributed and homogeneous. The results of the hypothesis testing showed that t-count > t-table (2.66 > 1.68) at a significance level of α = 0.05. Thus, H₀ was rejected and H₁ was accepted. Based on these results, it can be concluded that there is a significant effect of using the Problem Solving learning model on the mathematics learning outcomes of Phase F students in the TITL major at SMK Negeri 5 Padang.