An atomizer and an electronic cigarette having the same are provided, the atomizer includes a base; an adjusting ring fixed on the base and configured to adjust a volume of air inflow, the adjusting ring bored with a first air inlet; and an atomizing component partly received in the adjusting ring and being in rotatable connection with the base. Part of the atomizing component received in the adjusting ring is bored with a second air inlet corresponding to the first air inlet. When an external force drives the atomizing component excluding the part thereof received in the adjusting ring to rotate relatively to the base, an overlap ratio of the first air inlet and the second air inlet is capable to be adjusted.