In this paper, we present a chip-integrated receiver for electron paramagnetic resonance (EPR), designed for operation in the S-band (2-4 GHz). This EPR-on-a-chip receiver consists of a low-noise amplifier, followed by quadrature down-conversion mixers and intermediate-frequency variable gain amplifiers. It also incorporates a frequency generation block. The chip is realized in a 0.13-µm SiGe BiCMOS technology and occupies an area of 1100x900 µm^2. The receiver’s measured input-referred voltage noise density within the band of interest is 720pV/sqrtHz. Proof-of-concept EPR measurements validate the proposed approach.