Multiple centers are starting to use hyperpolarized 129Xe MR imaging and spectroscopy to quantify pulmonary function. This drives the need for standardization and quality assurance (QA), which is challenging for short-lived hyperpolarized agents. To address this, we developed a high pressure thermal 129Xe phantom constructed from high-density polyethylene and an associated loader shell that mimics the human torso. The phantom was imaged at 8 institutions across North America comprising a variety of scanners, vendors, coils, and field strengths. Image SNR measured with a minute-long scan agreed within a factor of 2 across sites and enabled rapid comparison of MR configurations.