It is the PFA's highest honour and will be presented to Salisbury at the union's annual players' awards night in Newcastle next month.
Defender Salisbury played 151 times for Australia between 1994 and 2009 and is a pioneer of women's football.
She started in the Matildas' first FIFA World Cup match in 1995 and played at three subsequent editions of the tournament - including two as captain.
She also scored Australia's first goal in women's Olympic football in 2000 and was named Australia's greatest female player by the Johnny Warren Football Foundation five years ago.
Previous recipients of the Alex Tobin Medal include luminaries such as Warren, Joe Marston, Mark Viduka, Craig Johnston, Frank Farina, Mark Schwarzer and Harry Kewell.
"It's many a time I've sat in those crowds and watched somebody else receive those awards, and to be the first woman as well, it's an amazing achievement after such a huge career that I've had," Salisbury said.