Comeback prime ministers (CBPMs), who return to office after a break, have been a notable, but conspicuously understudied, feature of several parliamentary democracies. This article provides the first ever comparative study of CBPMs. To make sense of the varying frequency of CBPMs in 18 established democracies from 1945 to 2024, we refer to competing party rationales of (re-)selecting prime ministers in different contexts, with the latter shaping the former. Apart from powerful presidents in semi-presidential regimes, the frequency of early replacements of prime ministers, the scope of alternations of the prime minister’s party, and the degree of intraparty personalization offer plausible explanations for the cross-national and temporal variation of prime-ministerial returns. While CBPMs have become less common since 1990, the remaining cases include some particularly powerful party leaders, underscoring the continuing importance of this neglected feature for understanding chief executive selection in established parliamentary democracies and beyond.