Can I gift a game on Steam that I already own?

You cannot gift a game directly from your Steam library. However, on the store page of a game you already own, you'll see a "Buy this game as a gift for a friend" option — this lets you purchase an additional copy specifically as a gift. If you have duplicate gift copies from bundles, go to Games → Manage Gifts and Guest Passes in the Steam client to send those. Alternatively, you can buy a Steam game key from a third-party seller and send the key directly.