The novel red-emitting Sr(Bi1–xEux)2B4O10 (x = 0.05, 0.10, 0.15, 0.20, 0.25, 0.30) phosphors were obtained by solid state reactions. Emission and excitation spectra of the Sr(Bi1–xEux)2B4O10 phosphors were investigated. The most intense band for all samples of the concentration series is in the region of 611 nm at excitation 392 nm. Distribution of the Eu3+ ions over cation sites was refined for x = 0.15, 0.20 and 0.30 from single-crystal X-ray diffraction data. In the SrBi1.70Eu0.30B4O10 and SrBi1.60Eu0.40B4O10 crystal structures, the Eu3+ ions occupy only the Bi2 site, then, the Eu3+ ions occupy 57 % of the Bi1 site and 3 % of the Bi2 site in the SrBi1.40Eu0.60B4O10 crystal structure. The asymmetry ratio is determined as the ratio of the integral intensity of radiative transitions 5D0–7F2 to 5D0–7F1 for Eu3+ ions. This means that the local environment of europium ions does not change or changes insignificantly. The optimal concentration is x = 0.25. It was shown by absorption spectroscopy, that the optical band gap for this sample is equal to 3.69 ± 0.01 eV. It has been demonstrated that if Eu3+ ions occupy the Bi1 and Bi2 sites, the Rc is considerably decreased, resulting in a change of energy migration in the crystal structures from one-dimensional to two-dimensional. The CIE chromaticity coordinates for the Sr(Bi1–xEux)2B4O10 phosphors were found to be (0.64, 0.35), which are in close proximity to the NTSC standard values of (0.67, 0.33) for commercial red phosphors. The obtained results show that the Sr(Bi1–xEux)2B4O10 phosphors are promising candidates for solid state lighting application.