A comprehensive review of millimeter‐wave antennas for telecommunications is presented. Major advances have been made in the past two decades on the development of lens and horn antennas to optically controlled millimeter‐wave antennas. In particular, a number of new antennas, such as extended hemispherical lens antennas, printed circuit antennas, active integrated antennas as well as photoconducting antennas, have resulted in excellent performance in millimeter‐wave frequencies. An attempt is made to categorize various mm‐wave antennas and to summarize the associated developments. An introduction to the concept of millimeter‐wave frequency band and its application is also presented at the beginning.