The Complete <i>Spitzer</i> Survey of Stellar Structure in Galaxies (CS⁴G)

Context. The Spitzer Survey of Stellar Structure in Galaxies (S 4 G), together with its Early Type Galaxy (ETG) extension, stands as the most extensive dataset of deep uniform mid-infrared (mid-IR; 3.6 and 4.5 μm) imaging for a sample of 2817 nearby ( d &lt; 40 Mpc) galaxies. However, the velocity criterion used to select the original sample results in an additional 422 galaxies without H I detection that should have been included in the S 4 G on the basis of their optical recession velocities. Aims. In order to create a complete magnitude-, size-, and volume-limited sample of nearby galaxies, we collected 3.6 μm and i -band images using archival data from different surveys and complemented it with new observations for the missing galaxies. Since most, but not all, of these galaxies have a Hubble type in Hyperleda T HL &gt; 0, we denote the sample of these additional galaxies as disc galaxy (DG) extension. We present the Complete Spitzer Survey of Stellar Structure in Galaxies (CS 4 G), encompassing a sample of 3239 galaxies (S 4 G+ETG+DG) with consistent imaging, surface brightness profiles, photometric parameters, and revised morphological classification. Methods. Following the original strategy of the S 4 G survey, we produced masks, surface brightness profiles, and curves of growth using masked 3.6 μm and i -band images. From these profiles, we derived the integrated quantities, including total magnitude, stellar mass, concentration parameter, and galaxy size, converting between optical i -band and 3.6 μm. We also re-measured these parameters for the S 4 G and ETG to create a homogenous sample. We present new morphologically revised T -types, and we showcase mid-IR scaling relations for the stellar mass, galaxy size, concentration index, and morphological type. Results. Our new masking procedure increases the number of pixels masked out by a factor of five, improving the masking of fainter regions over previous S 4 G data. Our photometric parameters from i -band imaging yield measurements consistent with the original sample (S 4 G) and its ETG extension in the 3.6 μm band. The new DG extension consists of galaxies with a wide morphological range (−5 &lt; T HL &lt; 10) and a mass range of 6 &lt; log( M ⋆ / M ⊙ ) &lt; 11. The galaxies in the DG sample have an average mass of log( M ⋆ / M ⊙ ) = 9.21, an average galaxy isophotal radius at 25.5 mag arcsec −2 of R 25.5 = 7.1 kpc, and an average concentration index of C 82 = 2.92. Conclusions. We completed the S 4 G sample by incorporating 422 galaxies into the original dataset. The new galaxies constitute 15% of the total previous sample (S 4 G+ETG), but in the lower-mass range ( M ⋆ &lt; 10 9 M ⊙ ), and the disc galaxy extension increases the sample by 36%. The CS 4 G includes at least 99.94% of the complete sample of nearby galaxies, meeting the original selection criteria based on a comparison with the NED database. We make the images and surface brightness profiles available to the community together with the conjunct catalogue of the whole CS 4 G dataset with consistent photometric measurements for 3239 galaxies. The CS 4 G will enable a wide set of investigations into galaxy structure and evolution, and it will complement the optical, near-IR, and mid-IR imaging that will obtained in the coming years with Euclid , Rubin, Roman , and other research projects.