| Alexander Armstrong | |
| Birth Name: | Alexander R. Armstrong |
| Birth Date: | 1897 9, df=y |
| Birth Place: | Warren, New South Wales, Australia |
| Ru Position: | number eight |
| Repyears1: | 1923 |
| Repteam1: | Wallabies |
| Repcaps1: | 2 |
| Reppoints1: | 0 |
Alexander R. Armstrong (6 September 1897 – 30 November 1973) was a rugby union player who represented Australia.[1]
Armstrong, a number eight, claimed a total of 2 international rugby caps for Australia.