The demand for absorption-dominated terahertz (THz) electromagnetic shielding materials is critical in THz devices or components for electromagnetic compatibility and protection. However, it is challenging to find out an ultrathin, absorption-dominated shielding material with high absorptivity in a broad range. Herein, we demonstrate the hydrogen iodine (HI) acid reduced graphene oxide (rGO) ultrathin paper as a promising candidate for absorption-dominated electromagnetic interference (EMI) shielding. By optimizing the conductivity and layered structures, rGO paper with thickness of only 13 mu m exhibited an absorption-dominated EMI shielding effectiveness (SE) of 21.09 dB in a broad band from 0.2 to 1.2 THz. Simple stacking of the rGO papers further improved the EMI SE up to 42.53 dB with a total thickness of 40 mu m. rGO papers can also be integrated into structured substrates for applications in different scenarios. Covering a single rGO paper onto the wedge structure array, a broadband THz absorption over 99 % can be achieved. Similarly, combining rGO papers and arrays of zinc pyramids, and the average SE and the max THz absorption were enhanced to 54.83 dB and 99.986 %, respectively. We believe this absorption-dominated THz shielding rGO paper paves an efficient avenue towards high performance THz shielding/absorption devices for diverse applications.