The wing-back is a free agent after being released from his contract at Tottenham last week. Sessegnon had a year to run on his deal.
Sessegnon is now working at Palace, where manager Oliver Glasner is a fan.
The Austrian first noticed the left-back when he spent time on loan at Hoffenheim.
Sessegnon endured an injury-plagued campaign last season and is now working his way to full fitness.