In this study, different nanocellulose (NC) products were manufactured from corncob residue (CCR) through sulfuric acid hydrolysis, formic acid hydrolysis, and TEMPO-mediated oxidation methods (the products were referred as SCN, FCN, and TCN, respectively). The properties of NC products and their impact on rheological behavior of paper coatings were comparatively studied. Results showed that compared to SCN and TCN, FCN exhibited large dimensions, limited negative surface charge, and poor stability in their aqueous suspensions, while the FCN aqueous suspension displayed the highest viscoelastic modulus due to the formation of highly entangled network. In paper coatings, SCN exhibited superior thickening and promoted rheological function due to their highly charged surface and strong interactions with pigments and immobilized water molecules, in comparison with other NC products. This study verified that the NC derived from CCR could be utilized as green and renewable additives to improve rheological properties for paper coatings.