["Family Relations, EarlyView. ", "\nAbstract\n\nBackground\nFathers' childbirth experiences are underexamined despite implications for coparenting and family functioning. Treating birth as a gendered, institutional process, we examined how adverse paternal experiences relate to fathers' subjective well‐being (SWB) in Israel's pronatalist context.\n\n\nObjective\nWe test an applied model in which negative birth experiences are linked to SWB via masculine gender‐role stress (MGRS) and assess whether perceived social support moderates these effects.\n\n\nMethods\nA cross‐sectional survey of recent Israeli fathers (n = 352; ≤6 months postpartum) was conducted to assess negative birth experiences, life satisfaction, positive/negative affect, MGRS, and perceived social support. Structural equation modeling estimated mediation and moderation.\n\n\nResults\nMore negative birth experiences were associated with lower life satisfaction and higher negative affect (not positive affect). MGRS accounted for a significant indirect association between negative experiences and both life satisfaction and negative affect. Perceived social support did not moderate the negative‐experience → MGRS path but independently related to higher life satisfaction and positive affect and lower negative affect.\n\n\nConclusions and Implications\nChildbirth is a family transition where hegemonic masculinity can be activated and destabilized. Negative paternal experiences are linked to diminished SWB, in part through MGRS, highlighting intervention targets. Family educators and perinatal teams should implement father‐inclusive preparation/debriefing, train staff in gender‐responsive communication, screen briefly for MGRS‐related distress with referral to peer/partner supports, and adopt policies that formalize father participation and bolster postpartum community supports to strengthen coparenting and early family resilience.\n\n"]