Rub chicken breasts all over with olive oil and lemon juice. Season on both sides with salt and pepper.
Grill chicken over medium-high heat, turning occasionally until chicken registers 165F, about 8-10 minutes of cooking. Transfer chicken to a cutting board to cool.
Once chicken is cool enough to handle, slice into 1/2-inch cubes and set aside.
In a small bowl, whisk pesto, vinegar, and honey until smooth. Season dressing with salt and pepper to taste.
Cook pasta according to package instructions until al dente. Drain and rinse with cold water until cooled and transfer to a large bowl.
Add grilled chicken, cherry tomatoes, green onion, feta, basil, and pesto dressing to bowl and fold until pasta is evenly coated. Season salad with salt and pepper to taste and refrigerate until ready to serve. Enjoy!