The film debuted at No. 6 on its opening weekend, while its domestic box office grossed $7,100,501. By the end of its domestic theatrical run, the film had grossed $21,274,717.
Coneheads received mostly negative reviews from critics. The review aggregator website Rotten Tomatoes gives the film a low score of 35%, based on 31 reviews with a consensus that reads, "Listless, crude, and overall uninspired, Coneheads offers further evidence that stretching an SNL sketch to feature length can be tougher than narfling a garthok." Roger Ebert gave the film 1 star out of 4, describing Coneheads as "dismal, dreary and fairly desperate" and the actors as unable to overcome an uninspired screenplay. Janet Maslin of The New York Times said the film "has its dopey charms", and that it is suitable for people who found Wayne's World too demanding.
The Los Angeles Times called it "an unusually companionable jape; in this world it makes perfect sense that the Coneheads' friends and neighbors never really register that there's anything terribly different about them. They're all-American eccentrics—even if they happen to come from the planet Remulak".
Audiences surveyed by CinemaScore gave the film a grade of "B+" on scale of A+ to F.
The film received some critical re-evaluation during the 2010s, with multiple writers noting its satirical take on an immigrant family experience and immigration enforcement (meant as an exaggeration of Reagan-era politics) became eerily politically relevant following the September 11 attacks.