Is Pluto a planet?

If we are talking about classical planets, the answer to the question is NO. Pluto is no longer considered as one of the classical planets. The reason for this answer is because Pluto was originally considered as the ninth planet from the Sun after it was discovered in 1930 by Clyde Tombaugh. However, it was in 1992 when its status as a planet was questioned after the discovery of other similar objects in the Kuiper belt.

It was in 2005 when a dwarf planet named Eris was discovered. Eris was 27% more massive than Pluto and this discovery led to the International Astronomical Union (IAU) to formally define the term planet in which Pluto was reclassified to that of a dwarf planet.