Originally available as part of the PC Prepare to Die Edition, the additional content will be released through XBLA and PSN on October 24.
The 'Artorias of the Abyss' expansion will add new explorable areas, bosses, enemies, non-playable characters and equipment, as well as an enhanced online player vs. player mode.
The new online match-making feature enables players to participate in battles with other users from around the world.
Transporting players 100 years into the past, 'Artorias of the Abyss' is said to span over ten hours of new gameplay.
Dark Souls sold well after its release on Xbox 360 and PS3 in October, with 1.5 million units shipped worldwide.
Dark Souls: Prepare to Die Edition, which launched for the PC on August 24, releases for consoles on October 26.
> Read Digital Spy's 'Dark Souls' review
> Read our full interview for 'Dark Souls: Prepare to Die'
Watch the PC announcement trailer for Dark Souls: Prepare to Die Edition below: