It really depends on where the party is and if the party includes adults which might make it a little more formal than an all-teen party.
What to wear to a bar mitzvah party as a guest. Have your hair loosely curled. Once the religious ceremony and the necessary steps are complete the boy or girl is now considered an adult in the eyes of the Jewish Community. If the event is at a reception hall hotel or private space at a restaurant opt for something a little fancier like a cocktail dress and statement jewelry.
For the ceremony most times male guests are given yarmulkes to wear. If you are looking for a cocktail dress that is more practical and wont date then you can never go wrong with a little black dress. Wearing a basic tweed sports coat will allow your son to stand out a bit from the crowd.
While there are no set traditional colors for Bar Mitzvah dresses black brown navy blue burgundy and ivory are appropriate as are other single-color dresses. What to wear Barbat mitzvah parties come in all shapes and sizes these days from casual kids-only parties at sports complexes to swanky cocktail-attire shindigs in nightclubs. Men are typically expected to wear a suit or slacks and a tie.
A simple shift dress or a pantsuit will work for these events just make sure it is modest enough to wear to the synagogue too. Complement the suit with a pressed button down shirt and tie. Start with your invitation.
On appropriate attire for a Bar Mitzvah party. Guests at a barbat mitzvah celebration generally wear dressy clothes for men either a suit or slacks tie and jacket and for women a dress or formal pantsuit. Sport a clean shave and comb your hair neatly.
As the guest to a Bar or Bat Mitzvah service andor party you need a basic blazer with a few pair of coordinating slacks ie. Jewish men cover their heads in a synagogue and out of respect guests at a bar mitzvah or bat mitzvah are encouraged to do so as well. Suits not only look awesome but can also give you a look of respect and decency for the religious affair.