Social science research is increasingly data-driven, rigorous, and policy-relevant, but is at risk of being devalued due to evidence of the prevalence of problematic research practices and norms. This has led to growing interest in transparency practices in the social sciences. At present, the bulk of this work is centered around randomized controlled trials, which constitute a small fraction of social science research. I propose three scenarios in which study pre-registration can be credibly applied to non-experimental research. I outline suggested contents for observational pre-analysis plans, and highlight where these plans should deviate from pre-analysis plans designed for experimental research.