Some of them were senior Reds, such as Alex Telles, Eric Bailly, Dean Henderson and Axel Tuanzebe, while many were current Academy players who switched clubs and levels to gain first-team experience and enhance their development.
Now that the curtain has come down on their campaigns, we're reflecting on the fortunes of 17 loanees below.
With some lifting silverware and others lighting up their respective divisions, it's safe to say the long-established process of loaning out players has paid dividends once again...
AMAD Flying forward Amad almost helped Sunderland gain promotion to the Premier League, after they finished sixth in the league, but they were eliminated in the play-off semi-finals by eventual winners Luton Town.
Games: 43 | Goals: 14 | Assists: 4