| Name | Edition | Colour | Type | Cost | Power | Rarity | $ |
|---|---|---|---|---|---|---|---|
| Obelisk of Undoing | CH | Artifact | Artifact | 1 | Uncommon | 3.06 | |
| Obelisk of Undoing | AQ | Artifact | Mono Artifact | 1 | Uncommon | 4.23 | |
| Obelisk of Undoing | 5E | Artifact | Artifact | 1 | Rare | 3.58 | |
| Oblation | ON | White | Instant | 2W | Rare | 2.51 | |
| Obliterate | IN | Red | Sorcery | 6RR | Rare | 3.91 | |
| Obliterate | 8E | Red | Sorcery | 6RR | Rare | 3.30 | |
| Oblivion Crown | FS | Black | Enchantment - Aura | 1B | Common | 0.11 | |
| Oblivion Ring | LW | White | Enchantment | 2W | Common | 0.56 | |
| Oblivion Stone | MI | Artifact | Artifact | 3 | Rare | 5.74 | |
| Oboro Breezecaller | SK | Blue | Creature-Moonfolk Wizard | 1U | 1/1 | Common | 0.10 |
| Oboro Envoy | SK | Blue | Creature-Moonfolk Wizard | 3U | 1/3 | Uncommon | 0.18 |
| Oboro, Palace in the Clouds | SK | Land | Legendary Land | Rare | 0.86 | ||
| Obsessive Search | TR | Blue | Instant | U | Common | 2.09 | |
| Obsianus Golem | UN | Artifact | Artifact Creature | 6 | 4/6 | Uncommon | 3.27 |
| Obsianus Golem | RV | Artifact | Artifact Creature | 6 | 4/6 | Uncommon | 2275.17 |
| Obsianus Golem | B | Artifact | Artifact Creature | 6 | 4/6 | Uncommon | 4.58 |
| Obsianus Golem | A | Artifact | Artifact Creature | 6 | 4/6 | Uncommon | 10.75 |
| Obsianus Golem | 6E | Artifact | Artifact Creature | 6 | Uncommon | 3229.15 | |
| Obsianus Golem | 4E | Artifact | Artifact Creature | 6 | 4/6 | Uncommon | 2944.29 |
| Obsianus Golem | CE | Artifact | Artifact Creature | 6 | 4/6 | Uncommon | 13.46 |
| Obsianus Golem | ST2 | Artifact | Artifact Creature - Golem | 6 | 4/6 | Uncommon | 0.43 |
| Obsidian Acolyte | IN | White | Creature - Cleric | 1W | 1/1 | Common | 2.62 |
| Obsidian Battle-Axe | MT | Artifact | Tribal Artifact - Warrior Equipment | 3 | Uncommon | 0.24 | |
| Obsidian Giant | PO2 | Red | Summon Creature - Giant | 4R | 4/4 | Uncommon | 4.25 |
| Obstinate Familiar | OD | Red | Creature - Lizard | R | 1/1 | Rare | 0.59 |