The open-science movement is driven by the desire to increase research transparency, accessibility, and equity in conducting, reporting, and sharing research. Because open science aims to enable access and inclusion, and because incivility impedes both access and inclusion, many open-science organizations endorse the need for interpersonal civility. In this article, we present empirically validated solutions for promoting interpersonal civility in both formal and informal open-science contexts. We begin by defining formal versus informal contexts, as well as illustrating the advantages of each for achieving open-science goals. We present publicly documented instances of interpersonal incivility that have occurred in both formal and informal contexts, and we conclude by presenting five scientifically supported recommendations for promoting civility in open-science formal and informal contexts.