Context. We present ASTRODEEP-GS43, a new multi-wavelength photometric catalogue of the GOODS-South field, which builds and improves upon the previously released CANDELS catalogue.Aims. We provide photometric fluxes and corresponding uncertainties in 43 optical and infrared bands (25 wide and 18 medium filters), as well as the photometric redshifts and physical properties of the 34930 CANDELS H-detected objects, plus an additional sample of 178 H-dropout sources, of which 173 are Ks-detected and five are IRAC-detected.Methods. We keep the CANDELS photometry in seven bands (CTIO U, Hubble Space Telescope WFC3, and ISAAC-K) and measure from scratch the fluxes in the other 36 (23 from Subaru SuprimeCAM and Magellan Baade FourStar and the rest from VIMOS, HST ACS, HAWK-I Ks, and Spitzer IRAC) with state-of-the-art template-fitting techniques. We then compute new photometric redshifts with three different software tools and take the median value as a best estimate. We finally evaluate new physical parameters from spectral energy distribution (SED) fitting, comparing them to previously published ones.Results. Comparing to a sample of 3931 high quality spectroscopic redshifts, for the new photometric redshifts we obtain a normalised median absolute deviation of 0.015, with 3.01% of outliers on the full catalogue (0.011 and 0.22% on the bright end at I814< 22.5). This is similar to the best available published samples of photometric redshifts, such as the COSMOS UltraVISTA catalogue.Conclusions. The ASTRODEEP-GS43 results are in qualitative agreement with previously published catalogues of the GOODS-South field, improving on them particularly in terms of SED sampling and photometric redshift estimates. The catalogue is available for download from the ASTRODEEP website.