Robert Ainslie was a Scotland international rugby union player. His playing position was Forward.
Ainslie played for Edinburgh Institution F.P.
Ainslie played for Edinburgh District in their inter-city match against Glasgow District on 1 December 1887 and on 4 December 1880.
Ainslie was capped by East of Scotland District in their match against West of Scotland District on 9 February 1878 and on 5 February 1881.
Ainslie played for Whites Trial in their match against Blues Trial on 16 February 1878.
Ainslie was capped seven times for Scotland between 1879 and 1882.
Ainslie was the brother of Thomas Ainslie who was also capped for Scotland.