The Mediterranean decor features light wood, warm clay plaster, leather, tile, and marble. The dining room is clad in richly textured tile and has a large fireplace and dynamic undulating ceiling with glowing, lantern-like pendant lights. The 30-foot-long open kitchen, showcasing Casa Dani's unique cooking techniques, is framed by a reflective box and sits opposite from the bar. High top tables, hanging plants, soft lace-inspired drapes, and a counter to carve salt-cured tuna charcuterie all reference the restaurant's Spanish origins. Olive trees and terracotta tiles create the impression of dining al fresco inside this New York City restaurant, designed to resemble a traditional Spanish courtyard. The interior of Casa Dani, much like its menu, was conceived to celebrate the heritage of head chef Dani Garcia, who hails from the region of Andalusia on the southernmost tip of Spain. Guests enter Casa Dani via a cozy lounge area with walnut parquet flooring, similar to what can be found in a typical Spanish villa.

One side of the room is dominated by a drinks bar with a countertop crafted from deep-green marble and a base clad in slender tiles of the same hue. The other side of the room is panelled in stainless steel sheets, behind which lies the restaurant's 30-foot-long kitchen. A band of glass running through the middle of the panels provides visitors with a direct view of the culinary theatrics that go into the preparation of each dish. Guests must walk down a staircase with a leather-wrapped bannister to reach the vast dining room, where both the walls and floors are inlaid with terracotta tiles. Paired with hanging plants, lantern-style lights and a smattering of olive trees, this creates the impression of being in one of the central open-air patios found in traditional Andalusian houses. Billowing lace curtains separate the banks of leather-upholstered seating, adding to the airy, al fresco feel. At the rear of the room, a towering fireplace is clad in glazed emerald-green tiles. Its rippling form is meant to echo the restaurant's ceiling, which is covered in a sequence of convex panels.