A D-band heterodyne integrated imager, consisting of a mixer, an oscillator, an IF amplifier, and an IF detector, has been developed in a 65-nm CMOS technology. A measured responsivity of 720 kV/W and noise equivalent power (NEP) of $0.9~{\rm pW}/{\rm Hz}^{1/2}$ were obtained at 125 GHz. A total dc power of 74 mW was dissipated. The chip size is $1200\times 800~\mu{\rm m}^{2}$ including contact pads and an input balun. A D-band image was acquired with the imager serving as a detector. A significant resolution enhancement was demonstrated with a near-field imaging achieved by a metal plate with a pinhole in the imaging setup.