The binary Zintl phase Ba₁₆Sb₁₁ has been synthesized and structurally characterized. Detailed studies via single-crystal X-ray diffraction methods indicate that although Ba₁₆Sb₁₁ appears to crystallize in the tetragonal Ca₁₆Sb₁₁ structure type (space group P (Figure presented.) 2₁m with a=13.5647(9) Å, c=12.4124(12) Å, Z=2, R₁=3.14 %; wR₂=4.77 %), there exists an extensive structural disorder. Some Ba₁₆Sb₁₁ crystals were found to be monoclinic and the structure was solved and refined in space group P2₁ (a=18.3929(12) Å, b=13.5233(8) Å, c=18.3978(12) Å, β=94.6600(10)°; Z=4, R₁=5.84 %; wR₂=9.58 %). The latter corresponds to a 2-fold superstructure of the tetragonal one, which provides a disorder-free structural model. In both descriptions, the disordered tetragonal and the ordered monoclinic superstructure, the basic building units that make up the structure of this Ba-rich compound are pairs of face-shared square antiprisms of Ba atoms, which are centered by Sb atoms. The dimerized antiprisms are linked into parallel chains via square prisms of Ba atoms, which are also centered by Sb atoms. The Zintl concept can be applied in a straightforward manner and as result, the structure of Ba₃₂Sb₂₂ (=2×Ba₁₆Sb₁₁) can be rationalized as (Ba²⁺)₃₂(Sb³⁻)₂₀[Sb₂]⁴⁻. The partitioning of the valence electrons is done taking into an account the homoatomic Sb−Sb contacts (d=3.01 Å), which can be clearly distinguished in the lower symmetry space group. Electronic structure calculations of Ba₁₆Sb₁₁ are in good accordance with the Zintl rationalization and predict a semiconductor with a band gap of 0.77 eV.