Cook the pasta according to the package instructions until al dente. Drain and let it cool completely.
Dice the avocado, halve the cherry tomatoes, and thinly slice the red onion.
In a large bowl, combine the cooled pasta, avocado, corn, cherry tomatoes, and red onion.
Whisk together the olive oil and fresh lemon juice in a small bowl.
Pour the dressing over the pasta salad.
Gently toss until all the ingredients are evenly coated, taking care not to mash the avocado.
Serve immediately or refrigerate for 20–30 minutes before serving for the best flavor.