Place the softened cream cheese in a large mixing bowl.
Beat with an electric mixer until completely smooth and creamy.
Add the sweetened condensed milk, fresh lemon juice, and lemon zest.
Continue mixing until the filling is silky smooth with no lumps.
Pour the filling into the prepared graham cracker crust.
Smooth the surface with a spatula.
Refrigerate the No-Bake Lemon Icebox Pie for at least 2 hours, or until fully set.
Top with whipped cream just before serving.
Slice and serve chilled for the best flavor and texture.