Two new 3-D isomorphous lanthanide(III) compounds [Eu₂(H₂L)₂(C₂O₄)₂]·2.51H₂O (1) and [Tb₂(H₂L)₂(C₂O₄)₂]·2.46H₂O (2, H₃L = glyphosate), based on glyphosate and oxalate have been successfully synthesized under hydrothermal conditions, and structurally characterized. In the two compounds, tetra-connected glyphosate ligands are coordinated to Ln³⁺, resulting in the formation of 1-D {Ln₂(H₂L)₂}_n double chains along the c direction. Each of the chains is connected to its four neighbors via the O atoms of phosphates of H₂L⁻ ligands, resulting in a 3-D (4, 6)-connected framework with 4³·5⁸·6³·7 topology, which possesses 1-D channels with oxalates and lattice water molecules as troglodytes. The oxalates are stabilized via chelating Ln³⁺ in the form of 1-D Ln-C₂O₄²⁻ zigzag chains along the c direction. To the best of our knowledge, compounds 1 and 2 represent the first single-crystal structures of lanthanide(III)-glyphosate compounds incorporating second ligands. The luminescent properties of compounds 1 and 2 have been investigated at room temperature. The energy gaps between the triplet excited state of oxalic acid and the lowest excited resonance levels of Eu³⁺ (⁵D₀) and Tb³⁺ (⁵D₄) are 7270 cm⁻¹ and 4070 cm⁻¹, respectively, indicating that oxalate is more suitable for the sensitization of Tb³⁺ luminescence than Eu³⁺ luminescence.