Salah, who shared this season's Premier League golden boot for the top scorer with Tottenham Hotspur's Son Heung-min, also won the award in the 2017-18 season.
The 29-year-old Egyptian scored 31 goals in all competitions for Liverpool and helped them win the League Cup and FA Cup.
"This one is a really good one to win, especially because it's voted by players. It shows you that you've worked really hard and you get what you worked for," Salah said.
"I have my room with trophies in a cabinet and I made sure that I had another space for one more. I always keep space and just try to imagine that the trophies are going to come."
Forward Kerr, who top-scored in the Women's Super League this season, became the first Australian player to win the PFA Players' Player of the Year award.
"It's a massive honor I think, whenever you're voted by your peers. I think that's the highest honor as a player so, it's an amazing feeling," said Kerr, who played a key role in Chelsea's domestic-double-winning team.
Manchester City's Phil Foden and Lauren Hemp retained their trophies for the Young Player of the Year, while former England coach Roy Hodgson and Brighton & Hove Albion Women's manager Hope Powell received merit awards for their contribution to the game.
"I never won any trophies as a player, unfortunately, so it is nice to be recognized by fellow professionals. It will have pride of place," said Hodgson, who announced his retirement last month after more than 40 years in management.