This study's aim was to research the ultimate loads and failure modes of single‐bolted pultruded glass‐fiber‐reinforced polymer (PGFRP) connections reinforced by glass fiber sheets (GFSs) under pin‐bearing conditions. In total, 144 specimens with various geometric parameters of GFRP bolted connections with different ratio values of the end distance of PGFRP plate to bolt diameter (e/d) and various ratio values of width of PGFRP plate to bolt diameter (w/d) were considered, and their results are here discussed (e/d = 2,3,4 and w/d = 2,3,4,5). Three types of GFSs (0°/90° GFSs, ±45°GFSs, and chopped strand mat GFSs) were molded by the vacuum‐assisted resin transfer molding (VaRTM) method and used to strengthen the connections. The results show that all three types of GFSs had good effects on the increase in the ultimate load of the connections. In addition, the strengthening effects were decreased with the increase in the e/d ratio of the connections for all types of GFSs. Moreover, theoretical equations were suggested to forecast the ultimate loads and failure modes of pin‐bearing single GFS‐strengthened PGFRP connections with high accuracy (less than 12% deviation).