Sometimes it can feel like anime - and pop culture, in general - focuses way too hard on romance. Though some of the best anime ever made focus partially or completely on matters of the heart, and there's nothing inherently wrong with these themes, they just aren't what everyone wants to see all the time. Whether you feel like the excessive focus on romance takes away from the plot elements that do interest you, can't get into the canon pairings that dominate your favorite shows, or just straight up don't want to see this kind of content, sometimes you want to watch anime with no romance.
It's nearly impossible to find anime with no romance whatsoever since it pops up in everything from kids' shows to horror. Still, there are plenty of shows that make minimal or no use of romantic tropes. What are some of the best anime without romance? That depends on your personal taste. If you like slice-of-life, you might want to try Barakamon, an anime about a young man trying to fix his troubled personality. If you're more of an action fan, maybe take on One Piece - it's one of the only shonen giants with no canon pairings to get in the way of the action.
No matter what your tastes are, there's something not-so-lovey-dovey out there for you to enjoy.
One Punch Man is a parody shonen about a superhero named Saitama who can defeat any enemy with a single punch. Besides using his incredible powers to protect the city, Saitama mostly just wants to watch TV and clip coupons - he doesn't seem to have any real inclination toward romance.
Though this doesn't apply to everyone in the series, no one is shown actually being in a relationship or attempting to pursue one.
Hunter X Hunter follows 12-year-old Gon Freecss on his journey to become a hunter, a title that will allow him great power and freedom, and may even help him find his long-lost father, Ging. Alongside him are many people seeking to advance their own hunter careers for a variety of reasons. Each story is more complicated and bizarre than the last, but none of them really focus on romance.
Though the show does deal with adult themes, the protagonist is quite young, which may explain this.
The Armed Detective Agency is a group of super-powered people who are all named after a figure from classic literature and who use their powers to solve mysteries and fend off the nefarious port mafia. Though there are some deep friendships between the characters, romantic relationships never develop.
Aside from Mob's unrequited crush on Tsubomi, which leads absolutely nowhere, Mob Psycho 100 is devoid of things romantic. Rather, it focuses on a 12-year-old boy learning to control his incredible psychic powers with the help of a loving mentor who is also a total con artist.
Together, they perform exorcisms, defeat cult leaders, and take down other psychics - all while trying to maintain relatively ordinary lives.