The rapid global spread of SARS-CoV-2 and resultant mortality and social disruption have highlighted the need to better understand coronaviral immunity to expedite vaccine development efforts. Multiple candidate vaccines with the goal of eliciting protective neutralising antibodies targeting the viral spike glycoprotein are rapidly advancing to clinical trial. However, the immunogenic properties of the spike in human populations are unresolved. To address this, we undertook an in-depth characterisation of humoral and cellular immunity against SARS-CoV-2 spike in humans following mild to moderate SARS-CoV-2 infection. We find serological antibody responses against spike are routinely elicited by infection and correlate with plasma neutralising and ACE2 inhibitory activity. Expanded populations of spike-specific memory B cells and circulating T follicular helper cells (cTFH) were detected within convalescent donors, while responses to receptor binding domain constitute a minor fraction. Using regression analysis, we find high serum neutralisation activity was associated with increased spike-specific antibody, but notably also with the relative distribution of some spike-specific cTFH subsets. Thus both qualitative and quantitative features of B and T cell immunity to spike constitute informative biomarkers to assess protective potential of novel SARS-CoV-2 vaccines