Ptolemy (c. AD 100 – c. 170) was a Greek mathematician, astronomer, geographer and astrologer.
Ptolemy may also refer to:
- Ptolemy (name), including a list of people with the name
- Ptolemy I Soter (303 – 282 BC), Hellenistic ruler of Egypt who established the Ptolemaic dynasty (305 BC – 30 BC)
- Mount Ptolemy (Antarctica)
- Mount Ptolemy (Canada)
- Tolomeo ('Ptolemy'), an opera seria by Handel
- "Ptolemy", a track by Aphex Twin from the 1992 album Selected Ambient Works 85-92