The present invention relates to a reverse flow prevention apparatus for common exhaust flue and a combustion apparatus having same. The reverse flow prevention apparatus for common exhaust flue, which is configured to collect exhaust gas of a plurality of combustion apparatuses, discharge the collected exhaust gas through a common exhaust flue, and prevent a reverse flow of the exhaust gas from the common exhaust pipe to each of the combustion apparatuses, includes a flange coupled to an exhaust port of each of the combustion apparatuses, an opening and closing apparatus hinge-coupled to an upper part of the flange to be opened and closed by a pressure difference between a lower portion and an upper portion thereof, and a body coupled to the upper part of the flange so as to accommodate the opening and closing apparatus. In accordance with the present invention, the reverse flow prevention apparatus, which may be directly installed at the exhaust port of the combustion apparatus, is coupled to the common exhaust flue upon installation thereof so that a separate certification may not be required to reduce time and costs for a certification.