Introduction: Mechanical neck pain (MNP) and mechanical low back pain (MLBP) can have a negative impact on the quality of life of patients and may be associated with high levels of disability. Magnetic field therapy has been using in the treatment of various diseases. This study was conducted to assess the effects of Static Magnetic Field (SMF) therapy generated by neodymium magnets in patients with MNP and MLBP. Methods: In this randomized, double-blind, sham-controlled, crossover study, patients with MNP and MLBP were randomly assigned to either the magnetic band or sham band treatment groups. After the initial 2-week phase (with participants randomly assigned to either treatment or sham-control), both groups underwent a 1-week washout period. Subsequently, the groups were swapped and proceeded with a second 2-week phase. Visual Analogue Scale (VAS), Oswestry Low Back Pain Disability Questionnaire (ODI), Neck Disability Index (NDI), Insomnia Severity Index (ISI), and Patient Health Questionnaire-9 (PHQ-9) were used to evaluate the patients' pain severity, functional disability, sleep quality, and levels of depressive symptoms, respectively. Results: Of the 30 subjects, 17 (56.7%) had MLBP, whereas 13 (43.3%) had MNP. Magnetic band treatment (MBT) resulted in a significant decrease in the VAS score (p < 0.001) in all patients. MBT led to a significant decrease in the ODI score (p = 0.009) in patients with MLBP. A significant decrease in the NDI score was found in MBT (p < 0.001) in patients with MNP. The improvement in ISI and PHQ-9 scores was also significantly higher in MBT (p < 0.001). Conclusion: For patients with MNP and MLBP who have not experienced sufficient benefits from conventional treatments, neodymium magnets can be considered as an alternative treatment option due to their significant properties.