Anderson Cooper is currently on assignment for CNN covering the growing violence between Israel and Hamas, which will prevent him from appearing on most of Monday's Anderson Live.
O'Donnell took to Twitter on Sunday (November 18) to reveal that she will return to daytime television today as guest host of Anderson Live.
She wrote: "I will fill in for Anderson cooper on his show Monday - as he is on assignment in Israel - nene leeks is my co host - #fun."
Cooper is expected to make an appearance on Monday's Anderson Live via satellite to provide updates on the Israel-Hamas conflict.
It is not yet known if Cooper will be hosting Anderson Live on Tuesday (November 20) or if other guest hosts will appear.
Anderson Live is in the midst of its second season, but Warner Bros has announced that the show will not be back for a season three.