The Advanced Mobile Phone Service (AMPS) is an American standard for analog mobile telephony, originally developed by AT&T. It has long been the dominant analog standard employed in the United States and has also seen usage in Canada, parts of South America, and select Pacific countries.

In the mid-1980s, AMPS was formally specified under the designation EIA-553. It operates within the 850 MHz frequency band, encompassing the ranges of 824-849 MHz for uplink and 869-894 MHz for downlink, with a channel spacing of 30 kHz. AMPS employs frequency modulation (FM) for its modulation scheme. Additionally, an alternative narrowband version known as N-AMPS, utilizing radio channels with a width of only 10 kHz, was introduced in the early 1990s.

AMPS adheres to the US Telecommunications Industry Association (TIA) IS-41 standard as the foundational network protocol.