This study evaluated the effects of dietary supplementation with Latilactobacillus curvatus CACC879 on growth performance, nutrient digestibility, faecal microbiota, faecal organic acid profiles, and malodour compounds in faecal slurry from finishing pigs. Sixty finishing pigs [(Landrace × Yorkshire) × Duroc; 30 males and 30 females; initial body weight, 54.98 ± 3.38 kg] were randomly assigned to one of two dietary treatments for 10 weeks: a basal diet (CON) or the basal diet supplemented with 0.25% L. curvatus CACC879 (1.2 × 1010 CFU/g; CACC879). Growth performance, nutrient digestibility, and faecal score were evaluated. Faecal samples collected from a subset of pigs on day 0 (D0) and day 70 (D70) were subjected to 16S rRNA gene sequencing and organic acid analysis. Hydrogen sulphide and methyl mercaptan concentrations in faecal slurry were measured using standard methods for offensive odour compounds. Dietary supplementation with L. curvatus CACC879 did not affect final body weight, average daily gain, average daily feed intake, feed efficiency, or faecal score, although energy digestibility tended to increase. On D70, CACC879 supplementation was associated with altered faecal microbial community structure and nominal differences in selected bacterial genera. In addition, the CACC879 group showed higher concentrations of selected faecal organic acids, including 2 methylbutyric, butyric, isobutyric, isovaleric, propionic, and valeric acids, while hydrogen sulphide and methyl mercaptan concentrations were reduced. These findings suggest that L. curvatus CACC879 may be a promising microbial feed additive for modifying faecal fermentation profiles and reducing sulphur-related odour compounds in finishing pigs without impairing growth performance.