The trio have been told they will leave St Andrew’s when their contracts expire next month.
Poland international goalkeeper Kuszczak, 37, has been with Blues since 2015 after joining the club from Brighton.
He last started a first-team match in November 2017, which was the final one of his 92 appearances.
Scottish midfielder Stewart, 29, moved to Blues from Dundee in August 2016 and has spent the past two seasons back on loan in Scotland at Aberdeen and Kilmarnock.
Ndoye, 33, joined Birmingham from French Ligue 1 club Angers on a free transfer in the summer of 2017.