Edwin Mee, 46, used his power to "abuse and bully" nine young women who were based in Croydon. One of them was aged 15, Southwark Crown Court heard.
The Glasgow-born officer, who served in Iraq and Afghanistan, was convicted of 16 offences.
The judge said Mee's actions had been "demeaning" and "distressing".
The sex assaults were carried out in 2011 and 2012.
Mee began his abuse by spanking women. It escalated to raping a vulnerable recruit.
Most of his victims were from overseas.
In total, the divorced father-of-five was found guilty of two rapes, one count of assault by penetration and 13 sexual assaults.
Judge Alistair McCreath told Mee: "What you did to each one constituted a serious abuse of trust."
An army recruitment sergeant has been jailed for 11 and a half years for raping and assaulting female cadets at Mitcham Barracks in south London.