The 27-year-old had another superb season in defence, polling 31.5 votes to narrowly edge out Irishman Pearce Hanley (30.5) and midfielder Jack Redden (26.5).
By statistics alone, Patfull had an even better season than 2012, when he won his inaugural best and fairest.
He led the Lions in total marks (114), spoils (140), and intercept possessions (135), while having more possessions, marks, rebounds and less clangers than last season.
Patfull – who has played 161 of a possible 162 games since his debut in 2006 – also won the Players’ Player of the Year and Shaun Hart Most Courageous Player awards.
He joins club legends Michael Voss, Simon Black and Jonathan Brown as the only players in the merged club's history to go back-to-back.
Hanley had arguably a career-best season and despite missing two games (one through suspension and one with a broken hand), trailed Patfull by just one vote.
Sam Mayes was named Rookie of the Year, while ruckman Matthew Leuenberger won the Marcus Ashcroft Most Professional Player award.
The club also inducted Graeme ‘Gubby’ Allan as a Life Member, along with current players Jed Adcock and Daniel Merrett.
Merrett-Murray Medal Voting ?
1. Joel Patfull – 31.5 votes
2. Pearce Hanley – 30.5 votes
3. Jack Redden – 26.5 votes
=4. Tom Rockliff – 25 votes
=4: Dayne Zorko – 25 votes
6. Matthew Leuenberger – 24 votes
7. Jed Adcock – 20 votes
=8. Brent Moloney – 18 votes
=8. Andrew Raines – 18 votes
10. Mitch Golby – 16.5 votes