Friday’s defeat was a record-equalling loss in the Premier League, with boss Ralph Hasenhuttl apologising and calling it a “disaster”.
The Saints squad has been in for training at the club’s Staplewood Campus over the weekend.
Hasenhuttl’s side are 18th and have just two league wins this season.
“The group has decided that they wish to donate their wages from the day of the Leicester game to Saints Foundation, in order to help the vital work that is conducted by the charity,” the club said in a statement.
-BBC