Wash the potatoes thoroughly under cold running water.
Cut the potatoes into uniform one-inch cubes.
Place potatoes in a large pot and cover with salted cold water.
Boil over medium-high heat until fork-tender, ensuring they remain firm.
Drain the potatoes in a colander and shake to remove excess moisture.
In a small bowl, whisk together the olive oil, lemon juice, salt, and pepper.
While the potatoes are still warm, place them in a large mixing bowl and pour the dressing over them.
Add the diced red onion, fresh dill, and Kalamata olives.
Fold the ingredients gently to coat the potatoes thoroughly without breaking them.
Serve at room temperature for the best flavor infusion.