A connector is provided for electrical connection to a flex circuit in a hermetically sealed manner. The flex circuit comprises thin film conductors encased between layers of insulative material, and including a proximal end with conductive contact pads exposed through one of the insulative layers. In a preferred form, the proximal ends of the two flex circuits are assembled in face-to-face relation and compressed by a clamp fixture against opposite side faces of a compressible terminal block. The terminal block is formed from a resilient insulative elastomer such as silicone rubber with embedded conductive strips having opposite edges exposed at the opposite side faces of the terminal block for electrically connecting aligned pairs of the contact pads on the two flex circuits. The exposed edges of the conductive strips are circumscribed by the insulative elastomer which engages the flex circuits with a footprint circumscribing the exposed contact pads, whereby the terminal block hermetically seals the interface between the conductive strips and the contact pads.