Bring the sugar and water to a boil in a medium saucepan, stirring occasionally until mixture becomes slightly syrupy.
Remove from heat and stir in cucumber. Cover and set aside to steep for 30 minutes.
Place a fine mesh sieve over a bow, l and pour syrup over to strain out solids. Use the back of a spoon to extract as much liquid as possible.
Store in an air tight container in the fridge.