Cook the couscous according to package directions. When it’s ready, fluff with a fork a couple of times so it cools a little.
Peel the oranges and seed them if necessary. Separate them into segments and chop them into bite-size pieces if you’d like. Transfer the oranges to a large salad bowl.
Trim the fennel and thinly slice crosswise to get a pile of crescent-shaped pieces. Pull apart any that stick together and discard any hard center pieces. Add the fennel to a bowl with the oranges.
Add the olives to the bowl along with the couscous. Drizzle in ¼ cup olive oil, sprinkle with salt and pepper, and toss to combine. Taste and adjust the seasoning, adding more olive oil if you’d like. Toss again and serve.