Background The exploration of inter- and intra-individual variability in suicidal ideation (SI) is vital to suicide research. However, this research relies on the identification and measurement of standardized SI characteristics. Objective This review aimed to identify characteristics of SI examined in research, describe how these characteristics are measured, and assess how they are aligned with those included in the Columbia Suicide Severity Rating Scale (C-SSRS). Methods Four databases were systematically searched, and relevant data was extracted. The C-SSRS provided a framework for comparing SI names, measures and operational definitions. Results After comparing operational definitions of identified characteristics, five core domains emerged: (1) severity, (2) temporality, (3) variability, (4) controllability, and (5) deterrents/reasons for ideating. Except for variability, all SI characteristics in the literature were congruent with those measured in the C-SSRS. Conclusions This review highlighted conceptual and methodologic inconsistencies in the study of SI, specifically the nomenclature, measurement and definitions of SI characteristics. Standardized approaches to the study of SI characteristics are needed. These approaches will enhance accurate and reliable measurement of SI, allow for findings to be synthesized across studies and propel the exploration of inter and intra-individual SI variability leading to more individualized and effective SI treatment.