Sharaf al-Zamān Ṭāhir al-Marwazī or Marvazī (Arabic: شرف الزمان طاهر المروزي; fl. 1056/57–1124/25 CE) was a physician and author of Nature of Animals (كتاب طبائع الحيوان البحري والبري Kitāb Ṭabāʾiʿ al-Ḥayawān al-Baḥrī wa-al-Barrī).
He was a native of Merv, part of the Khorasan region in modern-day Turkmenistan.