Add sugar, water, and blueberries to a saucepan over medium heat. Stir to combine. Continue to stir occasionally as the sugar dissolves, about 2 minutes.
Turn the heat to medium-low. Let the blueberries simmer for about 10 minutes without stirring.
Remove from heat. Let the blueberries and syrup cool completely to room temperature in the pan.
Once cool, strain the syrup through a fine mesh sieve.
Store in a glass jar or other airtight container in the fridge for up to 1 month.