Background: Metastatic renal cell carcinoma (mRCC) represents a challenging condition characterised by poor prognosis and limited response to chemoradiotherapy. In this retrospective study, we compared the survival outcomes of first-line ICI regimens versus single-agent TKIs in patients with mRCC from two centres in Saudi Arabia. Methods: This study included 84 patients diagnosed with clear cell mRCC between January 2016 and December 2023. Patients were grouped based on treatment regimens. Progression-free survival (PFS) and overall survival (OS) were analysed using Kaplan–Meier curves and Cox proportional hazards regression. Results: The median first-line PFS was 9.7 months (95% CI: 5.3–14.1) for the overall cohort, with no significant difference between the single-agent tyrosine kinase inhibitor (TKI) group (9.4 months; 95% CI: 6.4–12.4), combination ICI group (9.0 months; 95% CI: 0.0–24.9), and single-agent ICI group (21.2 months; 95% CI: 2.6–39.8; p = 0.591). The median OS for the overall cohort was 42.0 months (95% CI: 14.9–69.2), with the single-agent TKI group having a median OS of 33.3 months (95% CI: 0.0–71.7), the combination ICI group, 42.0 months (95% CI: 0.06–84.0), and the single-agent ICI group, 23.0 months (95% CI: 19.2–26.7; p = 0.73). In comparison, the ICI-based combination therapy group exhibited a higher ORR of 41.0% (95% CI: 26.3–57.8%), while the single-agent ICI group had an ORR of 20.0% (95% CI: 3.5–55.8%). Cox regression identified liver metastasis as a significant independent predictor of PFS (HR = 1.8, p = 0.043), while a lower Karnofsky Performance Status was a significant independent predictor of OS (HR = 3.5, p < 0.001). Conclusions: In real-world practice from Saudi Arabia, first-line, single-agent ICI therapy offers promising anti-tumour activity and non-inferior survival outcomes compared to standard ICI-based combinations and single-agent TKIs.