Fast handoff support is a basic requirement for an Internet-based wireless mesh network (WMN), aiming to guarantee mobile users continuous connection to the Internet, regardless of their physical locations or moving trajectory. Due to the multihop transmission of network-layer handoff signaling packets, handoff performance in WMNs can be largely degraded by the increasing number of wireless hops as well as the channel access contentions between data and signaling packets in the mesh backbone. However, these issues are ignored in existing handoff solutions and multichannel medium-access control schemes. In this paper, we address the seamless handoff support from a different perspective and propose a gateway scheduling-based (GaS) beamforming scheme for handoff support in single-radio multichannel multihop WMNs. Our proposed beamforming scheme can realize single-hop handoff signaling packet transmissions and eliminate the channel contentions between data and signaling packets. Simulation results show that the total handoff delay is significantly improved using our proposed GaS beamforming scheme under various scenarios, as compared with existing handoff solutions in multihop WMNs. In addition, due to the single-hop transmission of signaling packets, the signaling overhead in the wireless mesh backbone can be substantially reduced.