Delacour was established as a railway stop when the Grand Trunk Pacific Railway built its line through the area. The first passenger train officially rolled through the station on February 28, 1914. Later that year, the rail line was absorbed into the Canadian National Railway (CNR) network.

The hamlet and its station were named after a man with the surname De Lacour, who served as a foreman for the Grand Trunk Pacific Railway construction crew. While local lore long presumed the name was French meaning "of the court" or "of the heart", historical records later showed that Mr. Delacour was actually of Danish origin.

Following the arrival of the railway, a small general store was opened in 1914. Shortly after, an official postal service began operating on November 15, 1915. The first postmaster was Mabel McKinnon, who held the position until 1920. Around this time, local infrastructure—including grain elevators and irrigation/canals—helped the surrounding farming community thrive.

To foster social connection in the rural area, early residents established the Delacour Community Club in 1928, quickly followed by an Agricultural Society.