For me, there are no constellation nearest to the earth. constellation are several distant away from
earth."constellation are group of stars" consequently, i think it would be the sun. "sun" is not a constellation its a star, proxima centauri is the star closest to sun ,alpha centauri is a star located at centaurus constellation,centaurus constellation is a constellation nearest to the sun, earth is near from the sun, on the other hand, I read some books that centaurus constellation would be the constellation nearest to the earth. the alpha centauri is located in the centaurus constellation which is near to the sun. obviously, centaurus constellation is the nearest constellation from earth.