Fictibacillus arsenicus, also known as Bacillus arsenicus, is a bacterium. It is Gram-positive, motile, endospore-forming, rod-shaped and arsenic-resistant. Its type strain is Con a/3<sup>T</sup> (=MTCC 4380<sup>T</sup>=DSM 15822<sup>T</sup>=JCM 12167<sup>T</sup>).