Bring a large pot of salted water to a boil. Add the whole wheat pasta and cook according to package instructions, about 8-10 minutes, until al dente. Drain and rinse under cold water. Set aside.
While the pasta cooks, halve the cherry tomatoes, dice the cucumber, and finely chop the red onion and fresh dill.
Open the can of tuna and drain thoroughly. Flake the tuna gently with a fork into bite-sized pieces.
In a small bowl, whisk together olive oil, lemon juice, salt, and pepper to make the dressing.
In a large mixing bowl, combine cooked pasta, tuna, cherry tomatoes, cucumber, red onion, and dill. Pour the dressing over and gently toss until well coated.
Taste and adjust seasoning with more salt, pepper, or lemon juice if needed.
Cover and refrigerate for at least 30 minutes before serving to allow flavors to meld. Serve chilled or at room temperature.
