The 22-year old Frenchman, who had a spell with Swindon Town last season, has been given permission to find regular first team football with the Shrimpers and he is looking forward to joining the League Two club.
"It is a one-year loan deal and I am looking to get some games and some experience and then we will see what happens at the end of that," N'Diaye told Southend's official website.
"The football might be a little different in League Two but in my head I will play the same way on the pitch.
"Just because it is at a level lower than Palace it doesn't mean that I will do anything differently. I will work even harder than before to prove to myself."