Semiconductor devices based on gallium nitride (GaN) have attracted significant attention for a variety of high power and high frequency applications [1]. Among the wide range of devices based on GaN, Schottky diodes have been researched extensively for the past two decades [2-3]. They show excellent performance due to their high critical breakdown field strength and high-temperature resistance. Recently, analytical techniques such as electrically detected magnetic resonance (EDMR) and near-zero field magnetoresistance (NZFMR) have been successfully utilized to identify the roles point defects play in semiconductor device physics [4]. We report on EDMR and NZFMR studies on GaN Schottky diodes. To the best of our knowledge, these results are the first EDMR and NZFMR results ever reported on GaN Schottky diodes. In this work, n-type GaN Schottky diodes from [5] were utilized with Rhenium contacts deposited by electron-beam evaporation and sputtering. An intense isotropic single line with g = 2.0025(±0.0003) has been observed at low (85 MHz, and 500 MHz, see Fig. 1-2.) and high frequency (9.237 GHz, see Fig. 3.) at moderate forward bias (0.6 V). The measurements were carried out at room temperature. The intensity of the EDMR signal increases monotonically by about an order of magnitude with forward bias from 0.6 to 1.4 V. No signal was detectable with reversed bias. The line-width of the EDMR single line at all measured frequencies, that is 85 MHz, 500 MHz and 9.2 GHz, is about 12 G. This indicates that the line- width is likely due to hyperfine interaction with nearby magnetic nuclei. The EDMR and NZFMR signals were present only in diodes with Re-sputtered contacts and no signal was found in diodes with Re contacts deposited by E-beam evaporation in devices with the nearly identical ideality factors (1.03 and 1.02 respectively). Using electron paramagnetic resonance (EPR), a narrow single line with a similar g-factor (g = 2.0026) was previously observed in AMMONO GaN crystals and Mg-doped GaN epitaxial layers by [6], and was tentatively ascribed to a deep acceptor. These results indicate that NZFMR and EDMR measurements will provide fundamental understanding of electronic transport in GaN-based Schottky diodes. This work was funded by the Office of Naval Research under Grant N00014-22-1-2462 and supported by the Air Force Office of Scientific Research under Award No. FA9550-22-1-0308. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the Office of Naval Research or the United States Air Force. Approved, DCN# 0543-1813-24. [1] S. J. Pearton et al., J. Appl. Phys. 86, 1–78 (1999) [2] Yu Shao et al., J. Phys. D: Appl. Phys. 57 093001 (2024) [3] Noorah A Al-Ahmadi., Mater. Res. Express 7 032001 (2020) [4] C. J. Cochrane and P. M. Lenahan, J. Appl. Phys. 112, 123714 (2012) [5] A. Molina and S. E. Mohney, Mater. Sci. Semicond. Process. 148, 106799 (2022). [6] M. Palczewska et al., MRS Internet Journal of Nitride Semiconductor Research Vol. 3, 45 (1998)