Summer’s arrival also ushers in wedding season. If your latest invitation calls for a formal dress code and you’re unsure what that means, the standard guide for women is a floor-length gown or an elegant cocktail dress—something refined enough to match the sophistication of the occasion. To help, I’ve curated a selection of outfit ideas fit for a range of formal celebrations. I envisioned different wedding backdrops and styled looks accordingly. Jetting off to the French Riviera? Picture yourself in a flowing pastel-blue gown, accented with topaz earrings and delicate strappy heels. Attending a ceremony at the New York Public Library? A sleek, understated black dress will feel right at home. Heading to an Old Hollywood–inspired soirée? Channel Grace Kelly with a celadon gown, a sparkling rivière necklace, and a chic frame clutch.