The influence of different fat sources in pigeon diets on performance, gut morphology, digestive enzymes and colorectal microbiota of their squabs was investigated from hatching to 28 days of age. Parent White King pigeons (240 males and 240 females) were randomly assigned to four dietary treatments, each including six replications of 10 pairs (one pair per cage). Four hundred eighty newly hatched squabs were randomly allocated, and two squabs were raised by a pair of parent pigeons. Pigeons were fed a basal diet supplemented with 6% lard oil (LO), palm oil (PO), soybean oil (SO) or fish oil (FO), respectively. After four weeks of experimental feeding, FO inclusion caused the lowest body weight gain of squabs and the highest lipase activity in the jejunum content. Compared with other treatments, Group SO showed a greater villus height and duodenal surface area in squabs. In Group PO the alkaline phosphatase activity in duodenal mucosa of squabs was decreased, while in Group LO the alkaline phosphatase activity in the jejunal mucosa was highest. The leucine aminopeptidase (LAP) activity in the duodenal, jejunal and ileal mucosa of squabs was highest in Group SO. In the colorectal content of squabs, in Group LO the highest percentages of microbiota of the enteric group (Clostridium, Bifidobacterium, Coriobacterium and Bacteroides-Porphyromonas-Prevotella) were induced. Because supplementation of SO has beneficial effects on gut development and digestive function at comparable growth performance, it is probably a better choice for oil supplementation in parental pigeon diets.