Amino groups were successfully introduced to cellulose paper using a silane coupling technique, through the condensation reaction between Si–OH of the organofunctional silane coupling agent and C–OH of cellulose. The as-prepared paper material, denoted amine-modified paper, had excellent handling convenience and some degree of hydrophobicity, indicating that the silane coupling treatment enhances the physical strength and the hydrophobicity of cellulose paper. In the batch process of the Knoevenagel condensation reaction, the amine-modified paper demonstrated high catalytic efficiency and reusability, suggesting that the amino groups introduced to the cellulose paper can act as an efficient base catalyst. In addition, the porous structure of the paper allowed successful use in a flow process. Thus, cellulose paper modified with amino groups is a promising material for practical use in catalytic and other applications, and the silane coupling technique has great potential to develop an array of practical new functional paper materials.