Background: Obesity is strongly associated with impaired physical function and increased health risks. Functional performance tests such as the Timed Up and Go (TUG), Five Times Sit-to-Stand (5xSTS), and 4-Meter Walk Test (4MWT) are essential for evaluating mobility, strength, and gait speed. Although widely used in clinical practice, the reliability of remote tele-assessment of these tests in adults with obesity remains unclear. Objective: This study aimed to determine the inter- and intra-rater reliability of tele-assessment compared with face-to-face assessment for commonly used functional performance tests in adults with obesity. Methods: A repeated-measures observational study was conducted with 82 adults with obesity. Participants performed TUG, 5xSTS, and 4MWT tests both in a clinical setting and remotely at home using video-based tele-assessment. Results: Inter-rater reliability was good for TUG (ICC = 0.826) and 5xSTS (ICC = 0.880), and moderate for 4MWT (ICC = 0.743). Intra-rater reliability across two tele-assessments was excellent for TUG (ICC = 0.910) and 5xSTS (ICC = 0.902), and good for 4MWT (ICC = 0.858). Conclusion: Tele-assessment provides a reliable alternative to face-to-face assessment of functional performance tests in adults with obesity. These findings support the integration of remote functional testing into digital health practice, expanding access to mobility and strength evaluations for populations with limited access to in-person care. Clinical Trial Registration: Not applicable.