The present invention relates to a novel metallocene compound, to a catalyst composition comprising same, and to an olefin polymer prepared using same. The metallocene compound and the catalyst compound comprising same according to the present invention can be implemented to prepare an olefin polymer, have superior copolymerizability, and can be formed into a high molecular weight olefin polymer. Particularly, a block copolymer with superior heat resistance can be obtained from the metallocene compound of the present invention, and an olefin polymer having a high melting point (Tm) can be obtained even when the comonomer content is increased in preparing the olefin polymer.