Steve Mostyn (1963-2017) was a prominent Houston-based trial attorney known for his work in personal injury and mass tort litigation. He founded the Mostyn Law Firm in 2004, which grew into one of Texas's leading plaintiff's firms, securing multimillion-dollar verdicts in cases involving defective products, medical malpractice, and environmental disasters. Mostyn was also a major Democratic donor and political activist who supported progressive causes in Texas, channeling significant funds into efforts to combat Republican gerrymandering and support progressive candidates. His philanthropy extended to education and veterans' issues. He faced personal struggles, culminating in his death by suicide amid reported health challenges in 2017. Mostyn's influence in Texas politics was notable, as he helped fund key battles in the state's increasingly polarized landscape.