In a small saucepan over high heat, bring sugar, water and dill to a boil. Once the sugar is dissolved, remove from heat and cover. Let steep 30 minutes.
Strain into a airtight container. Refrigerate until ready to use.
To make the cocktail, add whiskey, dill simple syrup, and apple juice to a rocks glass filled with ice.
Top with ginger beer.
Garnish with freshly sliced apple and dill. Serve.