What was the name of the first commercially available smartphone?

The first commercially available smartphone was the IBM Simon.

IBM engineer Frank Canova developed the prototype, code-named Angler, and demonstrated it at the COMDEX trade show in November 1992. The commercial version was called the Simon Personal Communicator and was marketed by BellSouth Cellular in the United States beginning on August 16, 1994.

The Simon combined a cellular telephone with PDA features that were unusual for its time, including a touchscreen, calendar, address book, notepad, calculator, fax capability, email support, and a PCMCIA slot for additional software. It was manufactured by Mitsubishi Electric and used an analog AMPS cellular network.

The Simon was not a major commercial success: BellSouth sold approximately 50,000 units before discontinuing it in 1995. Its large size, roughly one hour of battery life, and price limited its appeal. Motorola DynaTAC phones were earlier mobile phones, but they did not offer the same integrated PDA functions.