Alzheimer's disease (AD) is the most prevalent cause of dementia, affecting one in nine people aged 65 years and older worldwide. Pathological hallmarks include the accumulation of senile plaques and neurofibrillary tangles, which are associated with changes in the levels of AD biomarkers, such as amyloid peptides and tau proteins. As the neuropathological process of AD commences decades before the onset of cognitive symptoms, an accurate assessment of AD biomarkers is critical for the early identification of at-risk AD patients. Photoelectrochemical (PEC) bioanalysis is a promising sensing methodology that exhibits superior sensing performance owing to the complete separation of the excitation source and detection signal. Numerous efforts have been made to develop PEC analytical platforms that target AD biomarkers. This review provides an overview of the recent advances in PEC sensing of AD biomarkers in body fluids. The major components of PEC sensing platforms (such as photoactive transducers, affinity agents, and targeted AD biomarkers) and PEC signaling strategies for detecting AD biomarkers are outlined. In addition, we summarize the current issues and strategies for advancing PEC sensing techniques to meet the ever-increasing demand for the early diagnosis of AD.