I don't think we can answer that as we are seeing fainter and fainter stars as technologies improve. The Hubble Space telescope showed stars never seen before but I am sure there are even fainter ones that we might see with new technologies one day.
Deneb is the dimmest star in Cygnus.
Gliese 229 is the dimmest star in the constellation Lepus
dimmest stars in aquarius
Castor
The dimmest star in the Phoenix constellation is HD 201626, which has an apparent magnitude of 5.59. It is a yellow-white F-type star located around 235 light-years away from Earth.
The dimmest star in the Pegasus constellation is likely to be one of its fainter stars, which may not have a common name but is listed with a designation such as HD 209087 or similar. These dim stars may be harder to observe with the naked eye or small telescopes due to their low brightness compared to brighter stars in the constellation.
The dimmest star in the constellation Aries is 40 Arietis, also known as Hamal. It is a binary star system with a primary component that is a spectral type K5III giant star, and it has an apparent magnitude of about 4.0, making it relatively faint compared to other stars in the constellation. While not the absolute dimmest possible, it is the least luminous among the prominent stars in Aries.
Algol is in the constellation Perseus.
Beta and Alpha Herculis are both 2nd Magnitude (2.78) stars
The dimmest star in the constellation Leo is generally considered to be Wolf 359. It is a red dwarf star located approximately 7.8 light years away from Earth and is known for its low luminosity.
Perseus is a constellation containing many stars but they are at very different distances. A constellation is a collection of stars in roughly similar directions, nothing else.
Alpha Persei (Mirfak or Algenib) is the brightest star in the constellation of Perseus.It has an apparent magnitude of 1.79 and an absolute magnitude of -4.50