Lava Cauldron is a Cauldron filled with lava, created by using a Lava Bucket on a Cauldron rather than on a crafting grid. A Lava Cauldron emits the maximum light level of 15 — the brightest value in Minecraft — and burns any entity that stands inside it, dealing the same fire damage as contact with an open lava source. Lava Cauldron holds the lava without letting it flow outward, so the block brings full-brightness lighting and a defensive hazard into a single tile. Lava Cauldron shares a hardness of 2 and a blast resistance of 2 with an empty Cauldron, and a wooden pickaxe or better is needed to retrieve anything from Lava Cauldron.

Survival players fill a Lava Cauldron either by emptying a Lava Bucket into a Cauldron or by placing a Cauldron under a downward pointed dripstone with a lava source above it, which slowly drips lava and fills the Cauldron for free — the same dripstone mechanic that makes lava a renewable resource. Builders use Lava Cauldron as a flat, contained light source where a flowing lava block would be dangerous, popular in mob farms that need light level 15 to suppress hostile spawns, in Nether-themed builds, and as a glowing floor tile. Lava Cauldron was added to Java Edition in 1.17 (snapshot 20w45a) and to Bedrock Edition in 1.9.0, and the block stacks to 64 in the inventory. Mining Lava Cauldron with a pickaxe drops an empty Cauldron and the lava is lost, while mining by hand drops nothing.