Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper.
Slice the zucchini into half-moons and the red onion into thin wedges.
Place the cherry tomatoes, zucchini, red onion, and kalamata olives on the prepared sheet pan.
Drizzle the vegetables with 0.25 tbsp of olive oil and sprinkle with 0.5 tsp of dried oregano, sea salt, and black pepper.
Toss the vegetables to coat evenly and roast in the oven for 10 minutes.
While the vegetables roast, pat the salmon dry with a paper towel and season with the remaining olive oil, lemon juice, minced garlic, and the rest of the oregano, salt, and pepper.
Remove the pan from the oven, move the vegetables to the edges, and place the seasoned salmon in the center.
Return the pan to the oven and bake for another 12-15 minutes, or until the salmon is opaque and flakes easily with a fork.
Remove from the oven and immediately top with crumbled feta cheese and chopped fresh parsley before serving.