After you receive the Goddess Sword, but before you leave Skyloft, speak with Instructor Owlan and he will give you a Wooden Shield. You must speak with him before you buy a shield at the Bazaar!

If you miss the free Wooden Shield (or if your first shield breaks and you need a new one) you can buy a Wooden Shield at the Bazaar in Skyloft for 50 rupees.

The Wooden Shield, and its upgraded forms, are weak against fire and strong against electric attacks.

Upgrade your Wooden Shield at the Scrap Shop in Skyloft to receive the Banded Shield.

Requirements:

50 Rupees	2 Amber Relic
1 Monster Claw	1 Jelly Blob

Upgrade your Banded Shield at the Scrap Shop in Skyloft to receive the Braced Shield.

Requirements:

50 Rupees	3 Amber Relic
2 Monster Claw	2 Tumbleweed
1 Ornamental Skull

The Iron Shield must be purchased from the Bazaar in Skyloft. The cost is 100 rupees, and the shield will not become available until after you complete the Skyview Temple.

The Iron Shield, and its upgraded forms, are weak against electric attacks and strong against fire.

Upgrade your Iron Shield at the Scrap Shop in Skyloft to receive the Reinforced Shield.

Requirements:

50 Rupees	2 Eldin Ore
2 Monster Claw	2 Ornamental Skull

Upgrade your Reinforced Shield at the Scrap Shop in Skyloft to receive the Fortified Shield.
Requirements:

100 Rupees	3 Eldin Ore
3 Monster Claw	3 Tumbleweed
1 Blue Bird Feather

The Sacred Shield must be purchased from the Bazaar in Skyloft. The cost is 500 rupees. This shield will not be available until after you have fought The Imprisoned at the Sealed Grounds after catching up with Zelda at the Temple of Time.

The Sacred Shield, and it’s upgraded forms, are resistant to both fire and electric attacks. These shields will also repair themselves when they are not being used. However, they can take fewer hits before they break, so be extra careful while using it!

Upgrade your Sacred Shield at the Scrap Shop in Skyloft to receive the Divine Shield.
Requirements:

100 Rupees	1 Dusk Relic
2 Bird Feather	3 Ornamental Skull

Upgrade your Divine Shield at the Scrap Shop in Skyloft to receive the Goddess Shield.
Requirements:

150 Rupees	4 Dusk Relic
3 Bird Feather	3 Monster Horn
1 Blue Bird Feather

Unlike all of the other shields, the Hylian Shield is obtained exclusively through a side quest. The Hylian Shield is the best shield in Skyward Sword and is completely indestructible.

To earn it, you must defeat eight bosses in-a-row in the Boss Rush mode organized by the Thunder Dragon. This mode will not become available until very late in the game.

During this competition, you will fight eight randomly selected bosses (though you get to pick the first one), but you will not be able to use any potions or take more than one shield with you. You can pick up hearts during the fights, but you cannot heal between fights.