There are differing views on whether the Messiah is already here:

Some Chabad Lubavitch followers believe Rabbi Menachem Mendel Schneerson, who passed away in 1994, was the Messiah24. They have put up billboards and signs proclaiming "Messiah is here!" referring to Rabbi Schneerson24. Some even believe he is still alive and will reveal himself2.

However, this is a fringe belief within Judaism4. The mainstream Jewish view is that the Messiah has not yet come15. Most Jews believe the Messiah is a future figure who has not yet arrived15.

In traditional Jewish belief, the Messiah could potentially come at any time, but has not revealed himself yet1. There is an idea that in every generation there is someone with the potential to be the Messiah if the time is right1.

Christianity, of course, believes Jesus was the Messiah who already came about 2000 years ago4. But this is rejected by Judaism5.

So in summary:

• A small group believes Rabbi Schneerson was/is the Messiah
• Mainstream Judaism believes the Messiah has not yet come
• Christianity believes Jesus was the Messiah who already came

The majority Jewish view remains that the Messiah is a future figure who has not yet revealed himself or arrived on the scene15.