Combine the sugar and water in a small saucepan over medium heat, stirring until the sugar has completely dissolved. Remove from the heat and allow to cool.
Add the frozen mango, the cooled sugar syrup, lime juice, and a pinch of salt to a food processor or high-powered blender.
Blend until completely smooth, stopping to scrape down the sides as needed. If the mixture is too thick to blend, add a little more syrup, 1 tablespoon at a time, until smooth and creamy.
Serve immediately as a soft-serve style sorbet, or transfer to a freezer-safe container and freeze for 2–4 hours for a firmer, scoopable texture.