This work experimentally investigated the heat transfer of a rotating porous cylinder under a circular impinging jet at the confined/unconfined conditions. The 0.93-porosity and 0.90-porosity aluminum foams were used. The dimensions of the Al-foam cylinder were 40 mm in diameter (D) and 20 mm in height (H) excepting the 4 mm-thickness spreader. Air was employed as the coolant. The diameter (d) of the circular nozzle was 20 mm. Relevant parameters included the rotational Reynolds number (Rer = 788–3163), the jet Reynolds number (Rej = 3325–16,690) and the relative impinging height (C/d = 0.05–9). The results indicated that, for the pure rotating condition, the average Nusselt number (Nur) of the unconfined system was higher than that of the confined system at C/d = 0.05, but there were few differences between these both systems at other values of C/d. For the pure jet-flow condition, on the contrary, the average Nusselt number (Nuj) of the unconfined system was smaller than that of the confined system at C/d = 0.05, while there were also few differences in Nuj between these both systems at C/d = 1–9. Besides, the Nur generally increased from C/d = 0.05 to C/d = 1, but changed little as C/d = 1–9. However, the Nuj declined with increasing C/d, especially for the smaller Rej. For the combined condition of the rotation and jet flow, the unconfined system had higher average Nusselt number (Nur,j) than the confined one at C/d = 0.05, especially for the bigger Rer. When the C/d increased, the difference of Nur,j between the confined/unconfined systems would decline. Besides, the rotational effect on the Nur,j was more substantial at the smaller Rej. Finally, according to all the experimental data, this work proposed the empirical relationships between average Nusselt number and Reynolds number for the confined/unconfined systems with various C/d.