The hamlet is located in Census Division No. 6 and in the federal riding of Bow River. The hamlet is represented in federal government by Member of Parliament Martin Shields and in municipal government by Councillor Rolly Ashdown.
Langdon was named for R.B. Langdon of Langdon & Shepard, a Canadian Pacific Railway subcontracting firm who built a section of the line just east of Calgary. He was born in Vermont in 1826 and worked on the railroad lines within at least ten US states, notably the St. Paul & Pacific Railroad in 1858. Langdon served as a state senator in Minnesota from 1873 to 1881. The nearby Shepard station was named for his partner. Langdon was one of two people to turn the first sod in the settlement in 1882. A year later, a railway station was set up in a boxcar and named after him.
A post office was established on January 1, 1890 and a telegraph office in 1899. Langdon incorporated as a village on August 31, 1907. It subsequently dissolved on January 1, 1946 to become part of the Municipal District of Conrich No. 44.
In 2018 the Rocky View County municipal census counted a population of 5,364 in Langdon, a 9.5% increase from its 2013 population.
Rocky View County's 2013 municipal census counted a population of 4,897 in Langdon, an 87.1% change from its 2006 municipal census population of 2,617. Its population in 2000 was 1,658.
In the 2011 Census, by combining its adjacent population centre and designated place geographies, Langdon had a population of 3,653 living in 1,125 of its 1,157 total dwellings, a 40.8% change from its 2006 population of 2,595. With a land area of 3.44 km2 (1.33 sq mi), it had a population density of 1,061.9/km2 (2,750/sq mi) in 2011.
As of 2006, Langdon had a total population of 2,595 living in 811 dwellings. With a land area of 3.33 km2 (1.29 sq mi), it has a population density of 779.3/km2 (2,018/sq mi).
These figures were derived from summing Langdon's urban area Statistics Canada data with its designated place Statistics Canada data. More specifically:
the Langdon urban area had a total population of 2,380 living in 739 dwellings within a land area of 1.80 km2 (0.69 sq mi), resulting in a population density of 1,322.2/km2 (3,424/sq mi); and
the Langdon designated place had a total population of 215 living in 72 dwellings within a land area of 1.53 km2 (0.59 sq mi), resulting in a population density of 140.1/km2 (363/sq mi).
Langdon's 2006 urban area and designated place boundaries are contiguous with no overlaps.
Langdon is home to the Boulder Creek Golf Course.
Langdon School provides education to students in kindergarten through grade 9. Sarah Thompson School provides education to students from K-5.