This study investigates the flow-induced vibration and heat transfer characteristics in three staggered cylinders of equal diameter using CFD simulations. The study focuses on a range of operating conditions, including Reynolds number (Re) of 100, the mass ratio of 2, reduced velocities (Ur) ranging from 2 to 14, and incidence angles θ = 0°, and θ = 30°. A user-defined function has been inserted into fluent solver to model the cylinder's vibration. The results indicate that as the gap ratio (G*) increases from G* = 2 to G* = 4, the flow pattern and oscillation amplitudes also change. It is found that for gap ratio (G* = 2), the oscillation amplitudes of cylinders are higher than gap ratio (G* = 4). Further, as angle of incidence increases, oscillation amplitudes of cylinders decrease and it is found minimum for θ = 30° and G* = 4. The angle of incidence and reduced velocity also influence the heat transfer. It is also found that as Ur increases, the Nusselt number (Nu) initially rises and subsequently declines for both gap ratios at θ = 0°. For G* = 2 and θ = 0°, the Nusselt number value is lower, and for G* = 4 and θ = 30°, the Nusselt number value is higher for all reduced velocities. The values of Nu for a range of reduced velocities are almost constant for G* = 4 and θ = 30°.