Armstrong is an unincorporated community in Kenedy County, Texas, United States.
Situated on U.S. Route 77, it was established in 1914, when the Missouri Pacific Railroad was extended to it. The community was named for John Barclay Armstrong, who established Armstrong Ranch nearby, in 1893. A post office called Katherine was established in 1913, before being renamed in 1915. As of 2000, it had a population of 20. The post office closed in 2011.
Armstrong has a humid subtropical climate (Köppen: Cfa). The all time record high of 111 ðF (44 ðC) was recorded on June 22, 2023, while the all time record low of 18 ðF (-8 ðC) was recorded on February 15th, 2021, January 26th and 27th, 2025.