Can you put Protection on an elytra?
No. You can't put Protection on an elytra in Java 26.3, not even with an anvil.
Why not
Protection is not on the elytra's list. Here is what an elytra can take instead: Curse of Binding, Curse of Vanishing, Unbreaking, Mending.
What that means in practice
The elytra gives no armor points at all, and it can't take armor enchantments. So wearing it instead of a chestplate costs you that chestplate's armor and its Protection. A netherite chestplate alone gives 8 armor points.
What to use instead
The elytra takes no armor enchantments: only Unbreaking, Mending and the curses. Most players wear a Protection chestplate in fights and swap to the elytra for flying. On a fresh elytra, Unbreaking III costs 3 levels and Mending costs 2 levels as a book.
Many players wear the elytra only while they travel. In Java, holding a chestplate and pressing use swaps it with the elytra you wear, so the switch takes a second.
See Unbreaking and Mending, or the full elytra build.
Why the game says no
Protection only goes on helmet, chestplate, leggings and boots. An elytra is not on that list. That matters because each enchantment's data file lists the items it supports, and the anvil checks that list. So the anvil gives no result, and the enchanting table never offers it.
No survival trick changes that. Combining two items, renaming or using a grindstone first all leave the list the same.
The best elytra build instead
So a max elytra has Unbreaking III and Mending. In the cheapest order it costs 6 levels over 2 anvil steps, and no step goes above 3. Open it in the calculator.
The best elytra enchantments page explains every book.
Where Protection goes
- Protection goes on helmet, chestplate, leggings and boots. The enchanting table can offer it on all of them. Related questions: Protection on shield.
Commands and creative mode
The /enchant command refuses too, because an elytra can't support Protection. Only /give with the enchantments component can attach it, which makes a command-only item that survival can never produce. The command generator writes the right syntax for your edition.
Java and Bedrock
As far as the item list goes, the answer is also the same in Java and Bedrock. The anvil differs, though: Java charges the full new level of every book. This page follows Java 26.3.
About Protection
Protection cuts almost every kind of damage: mobs, falls, fire, explosions and projectiles. Each level gives 1 protection point per armor piece, and every point removes 4% of the damage, up to the 80% cap. It is the one armor enchantment almost every build uses.
Protection has a max level of IV. If you need a book, you can get it from the enchanting table, librarian villagers, gear worn by trial chamber mobs and enchanted loot from fishing and chests. A librarian sells a Protection IV book for 14 to 58 emeralds. Before you buy, read everything about Protection, including what each level does.
What else an elytra can take
Instead, an elytra can take Unbreaking and Mending. Then the best elytra enchantments page ranks them and gives the max build.
Related questions: Mending on elytra, Unbreaking on elytra.
Questions
Can you put Protection on an elytra?
No. You can't put Protection on an elytra in Java 26.3, not even with an anvil.
What else can Protection go on?
helmet, chestplate, leggings and boots.
Can an elytra have Unbreaking and Mending?
Yes. Those are its only useful enchantments, and together they keep it flying for good.
Does an elytra give any armor?
No. It has 0 armor points, so you lose your chestplate's armor while you wear it.
How do I stay safe while flying?
Wear Protection IV on the helmet, leggings and boots, and Feather Falling IV for bad landings. Swap back to a chestplate for fights.
Can an elytra get Protection from an enchanting table or a villager?
No. The enchanting table only offers enchantments an item supports. A villager's Protection book still can't go on an elytra, because the anvil checks the same list.