Coherent imaging enables noninvasive, label‐free, and quantitative monitoring of the dynamic motions of transparent microobjects requested in life sciences, biochemistry, material sciences, and fluid mechanics. Quantitative phase imaging (QPI), a coherent imaging technique, provides full‐field optical phase information through light interference. The use of coherence, however, inevitably accompanies phase ambiguity and coherent artifacts, such as speckle, diffraction, and parasitic interference, which severely deteriorate the interferograms to hinder successful phase reconstruction. Herein, it is demonstrated that a frequency comb can newly provide a wide coherence tunability for higher visibility interferograms, phase‐coherent multiple wavelengths for extracting physical height information from refractive index, and higher phase stability (2.39 × 10−3 at 10 s averaging time) at a higher speed up to 16.9 kHz. These superior characteristics of frequency‐comb‐referenced QPI will enable in‐depth understanding of dynamic motions in cellular, biomolecular, and microphysical samples.