In a blender, combine the sliced strawberries and lemon juice. Blend until smooth. Strain the mixture through a fine mesh sieve into a large pitcher to remove the seeds and pulp.

Add the whiskey and simple syrup to the pitcher. Stir well to combine all the ingredients.

Fill glasses with ice cubes and pour the strawberry lemonade whiskey sour mixture over the ice.

Garnish each glass with a lemon slice and a fresh strawberry. Serve immediately.