Global climate change and habitat alteration are causing rapid declines in biodiversity, with insects especially at risk. Butterflies, as important pollinators and indicators of environmental health, exemplify these threats. This study examines two swallowtail butterflies in India- the Malabar Banded Peacock (Papilio buddha) and the Common Banded Peacock (Papilio crino) whose life cycles are tightly linked to their specific larval host plants. P. buddha is a Western Ghats specialist which depends exclusively on Zanthoxylum rhetsa (Rutaceae), whereas P. crino is more widespread and primarily utilizes Chloroxylon swietenia (Rutaceae), with Citrus limon serving as an alternate host. Western Ghats is a recognized biodiversity hotspot with many endemic species. The Western Ghats have experienced increasing monsoon variability and warming (extreme rainfall events and higher temperatures) which likely disrupt the delicate life cycles of these butterflies. Understanding how climate-driven changes will affect their ranges and plant dependencies is urgent for conservation. Ecological niche modeling (MaxEnt) was used to predict the current and future climatic suitability for each species, along with integrating their known larval host plant distributions. The projections were made under two Shared Socioeconomic Pathways (SSP1-2.6 and SSP5-8.5) for the near (2021-2040) and late (2081-2100) centuries. The results indicate that both species’ suitable habitats are likely to shift and contract under future warming scenarios. The specialist P. buddha is projected to undergo significant range contractions by mid-century under both emissions scenarios, with distributions shifting toward higher elevations and the southern Western Ghats. However, any potential stabilization by the late century remains minimal compared to its already restricted baseline range. This underscores its high sensitivity to warming and increasing monsoon variability within this biodiversity hotspot. In contrast, the generalist P. crino exhibits a distinct temporal response, with modest near-term range expansion under high-emission scenarios into the Indo-Gangetic plains and lower Himalayan foothills driven by milder winters. This is followed by substantial late-century contractions across scenarios as rising temperatures and increasing aridity limit the habitat suitability. These projections mirror broader patterns for butterflies: changing temperature and precipitation regimes directly alter habitat suitability. These findings highlight the tight coupling between butterflies and their host plants. Even small disruptions in plant phenology or distribution (for instance due to altered monsoon timing) could create mismatches. The modeled range losses for these butterflies underscore the urgency of conserving both the insects and their larval host plants. This study provides a concrete prediction of climate impacts on two iconic butterflies and emphasizes their ecological role. By combining ecological niche modeling with host-plant distribution, this study offers new insights into how tropical insect-plant interactions may unravel under climate change.