This dataset includes 3 measurements captured with full-field swept-source OCT in transmission (t-FF-SS-OCT) that were used in the manuscript titled "qtOCT: quantitative transmission optical coherence tomography". The measurements were recorded in an off-axis configuration by 2048x2048 CMOS camera with 5.5 μm pixel size (cam_pix). The swept-source with an 803-878 nm wavelength range was used as the light source. The numerical aperture (NA) and magnification (M) of the t-FF-SS-OCT system are 1.3 and -71.775, respectively. The measurements represent 3 experiments with different investigated samples: Experiment1.mat: PMMA microsphere (microParticles GmbH, diameter = 23.5 μm); Experiment2.mat: two PMMA microspheres (microParticles GmbH, diameter = 23.5 μm) with an additional glass coverslip covering only one microsphere (for more details, see the manuscript); Experiment3.mat: stomach wall cells (SWC) with and without scattering layer (SL) (for more details, see the manuscript); All files, Experiment1.mat, Experiment2.mat and Experiment3.mat, contain holograms captured for 751 wavenumbers in an off-axis configuration (offAxisHolo), but only the file Experiment1.mat includes numerically generated on-axis holograms (onAxisHolo). Reference holograms (without the sample in the field of view) are saved in files with the suffix "_ref". All holograms have been cropped to analyze specific ROIs. The .mat files also include reference-corrected OCT reconstructions (refCorrRecon), which can be temporally gated by the user-defined window to retrieve 2D integrated phases of the measured samples. Along with the dataset, a code implementation of the qtOCT (qtOCT_example.m) is provided for processing sample data from Experiment1.mat: onAxisHolo and onAxisHolo_ref.