C–C and C–S bonds are valuable in organic transformation for synthesizing various bioactive heterocycles. Owing to the increasing awareness of the step and atom economy of a reaction, organic chemists have promulgated the idea of sustainable and green chemistry for organic synthesis. Hence, photoredox catalysis using organic dyes as photocatalysts has attracted constant attention over the last decade. Herein, recent advances and developments (over the previous ten years, 2012–2022) in eosin Y mediated photoredox catalyzed synthetic organic transformations for C–C and C–S bond formation along with their different mechanistic pathways (such as SET, HAT, and energy transfer) are discussed. This review is classified into two major sections, (i) C–C and (ii) C–S bond formations, which are further sub-categorized into various types of functionalizations including arylation, alkenylation, annulation, thionation, and sulfonylation.