Eld's deer (Panolia eldii), also known as the thamin or brow-antlered deer, is an endangered species of deer indigenous to Southeast Asia. The species was first discovered by Westerners in Manipur in India in 1839. The original scientific name, Cervus eldi, was coined in 1844 in honour of Lt. Percy Eld, a British officer. The three subspecies of the Eld's deer are:

• Panolia eldii eldi: The Manipuri brow-antlered deer is found in Manipur, India. It is called sangai in Manipuri.
• P. e. thamin: The Burmese brow-antlered deer found in Myanmar, and westernmost Thailand.
• P. e. siamensis: The Thai brow-antlered deer is found in Cambodia, China, Laos, Thailand and Vietnam, and should perhaps be treated as a separate species. The population on the Chinese island of Hainan is sometimes considered another subspecies, P. e. hainanus, but this is not supported by genetic evidence. It was described by Lydekker in 1915.