The present study is aimed at unveiling the luminescence potential of Ba 4- x Sr 3+ x (BO 3 ) 4- y F 2+3 y (BSBF) crystals doped with Eu 3+ , Tb 3+ , and Ce 3+ . Owing to the incongruent melting character of the phase, the NaF compound was used as a solvent for BSBF crystal growth. The structure of BSBF: Eu 3+ with Eu 2 O 3 concentration of about 0.7(3) wt% was solved in the non-centrosymmetric point group P 6 3 mc . The presence of Eu 2 O 3 in BSBF: Eu 3+ leads to a shift of the absorption edge from 225 nm to 320 nm. The photoluminescence properties of the BSBF: Ce 3+ , BSBF: Tb 3+ , BSBF: Eu 3+ , and BSBF: Eu 3+ , Tb 3+ , Ce 3+ crystals have been studied. The unusual feature of europium emission in BSBF is the intensively manifested 5 D 0 → 7 F 0 transition at about 574 nm, which is the strongest for BSBF: Eu 3+ at 370 nm excitation and for BSBF: Eu 3+ , Tb 3+ , Ce 3+ at 300 nm and 370 nm excitations. No evidence of Tb 3+ →Eu 3+ energy transfer was found for BSBF: Eu 3+ , Tb 3+ , Ce 3+ . The PL spectra of BSBF: Eu 3+ at 77 and 300 K are similar with CIE chromaticity coordinates of (0.617; 0.378) at 300 nm excitation and (0.634; 0.359) at 395 nm excitation and low correlated color temperature which implies application prospects in the field of lightning. Due to the high intensity of 5 D 0 → 7 F 0 Eu 3+ transition at 370 nm excitation, the BSBF: Eu 3+ emission is yellow-shifted.