Spencer, 27, has scored 22 goals in 36 appearances this season, including 16 in 30 in the league, to help Farsley to the top of the table.
In the East Division, David Carson from champions elect Morpeth Town scooped the Player of the Year award.
Carson said: "I'm delighted. Targets set, targets achieved personally. One more to go, if we can win the league on Saturday then that's the icing on the cake.
"I put myself forward for this season and I believed in myself, and it's paid off."
Morpeth play in the Northumberland Senior Cup final at St James' Park on Tuesday night, while a win over Pontefract Collieries in the league on Saturday would secure the East Division title.
Atherton Collieries returned to the top of the West Division on Monday night, and the previous night, star man Ben Hardcastle was named the West Division's Player of the Year.
Premier Division Player of the Year: James Spencer (Farsley Celtic)
East Division Player of the Year: David Carson (Morpeth Town)
West Division Player of the Year: Ben Hardcastle (Atherton Collieries)