Thermochronometry is used to better understand the processes responsible for Cenozoic magmatism and exhumation of the Chiapas Massif Complex (CMC) that spans a diffuse triple junction between the Caribbean, North American and Cocos plates. A combination of zircon U-Pb, apatite fission tracks, (U-Th)/He and numerical modeling show contrasting histories. Exhumation started earlier in the south (16 Ma) relative to the north (~9 Ma). Northern exhumation is related to activity on the Tonalá fault, while to the south it may be correlated with transpressive deformation in the Sierra de Chiapas. The southern block also experienced significant topographic growth from ~5 Ma to ~1 Ma followed by intense erosion. Overall, the pattern of uplift is in agreement with the ‘closing zipper’ model. Thermal models also support a Pleistocene decrease in topography consistent with independent paleoenvironmental and geomorphological evidence.