The 20-year-old wins the award for the second month running following some excellent displays for the Hammers, capped by his fine solo goal in the 3-0 victory over Tottenham Hotspur at White Hart Lane in the London derby on the 6th October.
Morrison also contributed well in the 3-1 home defeat to Manchester City and the goalless draw when the Hammers visited Swansea City.
Goalkeeper Jussi Jaaskelainen was third in the vote with 32% and James Tomkins was third.