Decide between a tuxedo jacket and a dark suit jacket. Prom is a semi-formal event, so you'll either need a tuxedo jacket or a suit jacket that can mimic the tuxedo look. An actual tuxedo jacket will make you look sharper, but suit jackets are the cheaper option.[5]
If you do go with a tuxedo, rent instead of buy. Tuxedos are expensive, and since you're still growing at this stage of your life, you'll likely only use this piece once.
At the rental place, let them know that you are looking for something with a modern fit.
Go with a plain black jacket, regardless of whether you use a tuxedo or a suit.
The jacket should either have a peaked lapel or a shawl collar, and the lapels can either be faced in black satin or in the same fabric as the rest of the jacket.
Also make sure that the jacket has a buttonhole for you to place the boutonniere in.