Waddecar, 29, scored 25 goals to help Brig survive relegation from the Premier Division, and has been with the club since 2010.
Manager Joey Collins said: "It's a massive boost not just for the staff, but the players and supporters as well.
"Ali was one of the leading scorers in the league last season and is looking at breaking the club's all time appearance record, so it's a really big coup for us to have him on board for another season.
"Mine and Matt's key aim at the end of last season was to get Ali to put pen to paper and he's done that, which obviously we're over the moon with.
"It gives everybody a boost to have a player of that quality extend his contract, to buy into what we're trying to do and to carry us forward."
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