Manchester United's young keeper completed his loan spell with the Silkmen by picking up three individual awards as recognition for his efforts over the course of the campaign.
The 23-year-old won Town's Player of the Year, Players' Player of the Year and Young Player of the Year for 2018/19.
O'Hara was outstanding in keeping a clean sheet in a 1-0 victory at Port Vale in Macclesfield's penultimate game, which left matters in their own hands going into the final weekend.
Notts County were, ultimately, the club relegated to the National League, following a 3-1 reverse to Swindon Town.