Hydroxyl groups are generally treated as electron traps in organic field-effect transistors (OFETs), which make it difficult to achieve high electron transport at the interface of organic hydroxyl-containing dielectrics and organic semiconductors. Here, we adopted the drop-pinned crystallization (DPC) method to obtain well-aligned C60 single-crystal ribbons on different hydroxyl-containing polymer dielectrics, such as polyvinyl alcohol (PVA), poly 4-vinyl phenol (PVP), and got a high electron mobility (more than 1 cm2 V-1 s-1). Single crystals used here were good candidates for investigating the intrinsic electrical properties of organic semiconductors owing to high orientation and purity. Also, the ambipolar performance of 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pentacene) was firstly observed in PVP dielectric FET devices (average hole mobility: 0.436 ± 0.266 cm2 V-1 s-1, average electron mobility: 4.58 × 10-2 ± 4.82 × 10-2 cm2 V-1 s-1). These findings reveal that well-aligned single crystals can show excellent electron transport even on the surface of organic hydroxyl-containing dielectrics.