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We’ve reviewed dozens of formal dresses from sustainable brands — these are our top picks for comfort, style, and fit for your next cocktail party or black tie event.

We all know how the onslaught of social events can make it all too easy for fast-fashion dresses to pile up in our closets, getting only a few uses a year. One solution is to rent a dress, which is a great option when we have a single black-tie event in a season of beach receptions and we know we won’t get a chance to recycle the look. When we do buy, we can opt for dresses made with fair trade practices to ensure all employees are paid living wages while working under safe conditions, using materials that won’t harm the planet.

What sustainable materials make the best formal wear?

When it comes to sustainable formal wear, natural and lower-impact fabrics are usually your best bet because they look luxurious while being gentler on the planet. Materials like organic cotton, linen, hemp, TENCEL™ Lyocell, peace silk, and responsibly sourced wool are popular choices thanks to their breathability, durability, and timeless feel, while recycled fabrics like recycled polyester or deadstock satin can help reduce textile waste without sacrificing elegance. For evening wear, fabrics such as silk alternatives made from cupro, bamboo lyocell, or ECOVERO™ viscose can create that soft, drapey look people love in formal outfits without relying as heavily on resource-intensive production. The key is to look for well-made pieces designed to last for years — not just one wedding, gala, or holiday party — so your formal wear becomes something you genuinely rewear instead of something that ends up forgotten in the back of your closet.

What are the relevant certifications?

When shopping for sustainable formal wear, certifications can make it much easier to tell whether a brand is genuinely eco-conscious or just using clever marketing buzzwords. Some of the most helpful labels to look for include Global Organic Textile Standard (GOTS) for organic fabrics, OEKO-TEX Standard 100 for fabrics tested for harmful substances, and Fairtrade for better labor practices and worker protections. If you’re shopping for silk, wool, or leather formalwear, certifications such as the Responsible Wool Standard (RWS), peace silk, or Leather Working Group (LWG) approval can indicate more ethical sourcing practices. You may also spot recycled-material certifications like the Global Recycled Standard (GRS), which helps verify that fabrics made from recycled fibers are the real deal and produced with stricter environmental and social standards in mind.

Our criteria:

The Good Trade editors have over a decade of experience writing about slow and sustainable fashion. We’ve researched and corresponded with eco-friendly and ethical brands to compile this list of sustainable cocktail and wedding guest dresses. Each one of the brands we’ve featured meets the following criteria:

  • ETHICAL PRACTICES | These formal dresses are made by sustainable brands that adhere to ethical, responsible labor practices, ensuring employees receive fair wages and work in safe environments. We’ve also included dress brands that give back to their communities and prioritize size inclusivity in their offerings.
  • ECO-FRIENDLY/SUSTAINABLE | Each dress collection is made by a brand that practices sustainability throughout its manufacturing process, including using all-natural and organic materials, low-impact processes, and recycled/upcycled materials in its dresses where possible.
  • DESIGN | From flowy sundresses to chic and form-fitting cocktail attire, we’ve compiled a roundup of dress designs for every possible occasion and need.

These stunning dresses are perfect for any formal event or occasion — and they’re made ethically. Just don’t forget ethical jewelry to complete your look!


1. Reformation

Circular fashion
Climate neutral
Eco friendly packaging
OEKO-TEX® certified
Recycled materials
Size inclusive
Woman owned

Based In | Culver City, CA
Best For | Glam dresses
Price | $98–$980
Sizes | XSP–3X

Reformation puts people, and the planet, at the center of everything they do: ¾ of their team are women or from underrepresented populations; they also employ sustainable practices through and through, from their supply chain to supporting employees’ use of public transportation. We love their detailed filter options, letting you sort through their extensive collection by fabric, pattern, sleeve length, and even sustainability! Most of their sustainable dresses are made with TENCEL, viscose, or linen, creating that lightweight yet flattering look, no matter where you are. Pair these with wedge sandals and a small clutch, and you’re all set for the wedding of the year.


2. Sézane

B corp
Eco friendly packaging
FSC
GOTS certified
Gives back
Natural materials
OEKO-TEX® certified
Recycled materials
Woman owned

Based In | Paris, France
Best For | Guest dresses for summer weddings
Price | $145–$315
Sizes | XXS–XXXL

Sézane offers glam dresses perfect for holiday parties or weddings, seamlessly blending elegance with versatility. Each piece is thoughtfully crafted from the finest materials, with a focus on responsible production and impeccable design. Guided by a commitment to sustainability, Sézane avoids overproduction, unsold stock, and sales by releasing timeless designs and reintroducing archival pieces twice a year to ensure nothing goes to waste. Their dedication extends to philanthropy through the DEMAIN program, which has raised over €10 million to support education, health, and culture globally.

Our Editor’s Review | “It was love at first sight but I was afraid it wouldn’t last. Now after wearing Sézane, I know my feelings are deep and true, J’aime. Each of these pieces will be a lasting heirloom I hold onto for years to come. Not only because of their timeless style but their quality.” – Courtney Jay Higgins, Contributing Editor [Read our full review.]


3. Quince

Budget friendly
Eco friendly packaging
Natural materials
OEKO-TEX® certified
Size inclusive

Based In | San Francisco, CA
Best For | Affordable reception dresses
Price | $30–$150
Sizes | XS–XL

San Francisco-based Quince is known for its affordable and sustainable classic clothes, perfect for timeless capsules. The company keeps prices low by shipping directly from its factories, cutting out costly middlemen and excessive packaging to boot. Slide into one of their washable silk slip dresses or try a fit-and-flare number made from TENCEL Lyocell, a fiber extracted from sustainably grown wood using a closed-loop system that minimizes the environmental impact of production. 

Customer Review | “This dress is so flattering on! The fabric is so soft and silky! Very impressed.” – Lindsey E. (Read all reviews.)


4. Rujuta Sheth

BIPOC Owned
Circular fashion
Eco friendly packaging
Fair trade
Gives back
Handcrafted
Natural materials
Recycled materials
Size inclusive
Small business
Woman owned

Based In | New York City, NY
Best For | Colorful, patterned dresses
Price | $180–$268
Sizes | XS–4XL

Rujuta Sheth’s dresses are a perfect blend of bold, modern style and thoughtful sustainability — ideal for anyone looking to wear something colorful and unique to a casual cocktail gathering. Inspired by her Indian roots and global travels, Rujuta combines handwoven, organic fabrics with timeless silhouettes that feel effortlessly chic. Her pieces celebrate traditional artisan techniques like beading and embroidery, while staying rooted in ethical production and conscious design. Though the brand isn’t 100% sustainable yet, it’s deeply committed to using natural materials and creating long-lasting fashion that supports skilled craftspeople.

Customer Review | “This is such a fabulous dress! I have worn it with a scarf tied around my waist as a very wide belt. I have gotten so many compliments on it, and I’ve only worn it twice so far. It feels versatile as well, like it can be for a fun, more casual occasion, or a slightly fancy occasion as well. I’m so glad I bought it!” – Petaluma L. (Read all reviews.)


5. Rent The Runway

Budget friendly
Recycled materials
Second hand
Subscriptions available
Woman owned

Based In | New York, NY
Best For | Dresses for galas & fundraisers
Price | $78–$3,690; subscriptions available with plans starting at $129
Sizes | 0–22

A nontraditional (yet feasible!) option for fair trade formal wear is Rent The Runway. Customers can rent a dress of their choice, casual or formal, for a set amount of time and return it after that special occasion, without the heavy price tag. When the average woman throws out 82 pounds of clothing a year, it’s easy to see how it can all add up to a more polluted world. Instead, RTR makes it easy with thousands of affordable options that suit any event. This is the solution for those who need “special occasion” dresses to show off several times a year for fundraisers and galas, considering many of their brands are high-end designers.

Customer Review | “Rent the Runway lets me try pieces out of my comfort zone — it gives me freedom to wear clothing that I would realistically never get the chance to wear.” – thebobbedbrunette (Read all reviews.)


6. Christy Dawn

American made
Circular fashion
Climate neutral
Recycled materials
Size inclusive
Woman owned

Based In | Los Angeles, CA
Best For | Bridal & baby shower dresses
Price | $88–$498
Sizes | XXS–XL

Christy Dawn knows that everything we do impacts the planet and its people: “No matter how a piece of clothing looks, it cannot be considered beautiful if, in producing it, the environment is destroyed or people are exploited.” That’s why this stunning brand uses only deadstock (the residual fabrics leftover from other fashion houses) that are sewn together by seamstresses in Los Angeles, who are paid fair wages and given benefits. The outcome? Romantic, feminine, and flirty dresses with tulip sleeves, floral designs, and flattering fits.

Customer Review | “Like all the other dresses I have purchased from Christy Dawn, I’m absolutely in love! So comfortable and flattering 🙂 – Frances E. (Read all reviews.)


7. Xirena

American made
Natural materials
Woman owned

Based In | Los Angeles, CA
Best For | Guest dresses for destination weddings
Price | $178–$625
Sizes | XS–XL

LA-based brand Xirena mindfully crafts laidback formal wear that looks chic and effortless. Many styles are both designed and made right here in the US, and each style is well thought out to reflect timeless California style. We love how you can dress up or dress down these styles so you can get multiple uses out of them for a variety of occasions! View their lookbook for inspiration on how to style your Xirena piece.


8. EILEEN FISHER

B corp
Circular fashion
Fair trade
Natural materials
Second hand
Size inclusive
Woman owned

Based In | New York, NY
Best For | Dresses for casual weddings & gatherings
Price | $148–$498
Sizes | PP–3X

EILEEN FISHER, a longtime pioneer in human rights and sustainability, has put the well-being of the planet and its people at the core of its business model. So much so that their employees are all fair trade, nearly all of their materials and fabrics are sustainable, and they donate to girls’ and women’s empowerment initiatives regularly. Using TENCEL, organic cotton, and viscose, their dresses are perfect for that coworker’s engagement party or an extended relative’s birthday. What we love most about EF’s range is that they work for any season — pair with a boot or leggings in the fall, or slip on some sandals, and you’re all set.

Customer Review | “The minute I saw this dress I had to have it and it does not disappoint. Perfect cut, beautiful color and fabric, love this for spring and summer!! I bought with linen sweater and have already worn twice. Like my favorite Eileen clothes, it will be a go to and I will have and love it forever!” – LRob (Read all reviews.)


9. LILYSILK

Eco friendly packaging
FSC
GOTS certified
Gives back
Natural materials
OEKO-TEX® certified

Based In | Nanjing, China
Best For | Modest cocktail & wedding guest dresses
Price | $109–$990
Sizes | P–XXL

Known globally for its beautifully crafted silk and merino wool pieces, LILYSILK offers timeless dresses in a wide range of silhouettes, including plenty of chic, modest options that work beautifully for weddings, work events, dinners, religious celebrations, or everyday elevated style. What makes the brand especially stand out is its commitment to sustainability and craftsmanship, using premium certified materials like OEKO-TEX certified silk and ethically sourced merino wool while focusing on limited production runs to help reduce waste and overproduction. We love the flowy silk maxis and sophisticated long-sleeve designs that feel effortlessly modern, polished, and incredibly luxurious!

Customer Review | “I was worried about ordering such an expensive item, on sale, and thus non-returnable. However, this dress is perfectly as advertised – quality, color, and MEASUREMENTS! It fits perfectly, and I am no easy fit! – Thank you for creating a happy customer.” – Katherine (Read all reviews.)


10. Cuyana

Circular fashion
FSC
GOTS certified
Gives back
Natural materials
OEKO-TEX® certified
Recycled materials
Warranty offered
Woman owned

Based In | San Francisco, California
Best For | Versatile dresses
Price | $239–$523
Sizes | XS–XL

If you love dresses that make getting dressed feel effortless, Cuyana creates beautifully versatile pieces that can easily be styled up or down. Their feminine silhouettes feature thoughtful details like flowing tiered skirts, relaxed sleeves, button-front designs, and practical side pockets, and are crafted from materials like lightweight TENCEL™ fabric that feels silky-soft, breathable, and comfortable to wear all day long. With OEKO-TEX and FSC-certified materials plus a strong focus on timeless design over fast fashion trends, Cuyana delivers the kind of elevated wardrobe staples we keep reaching for year after year.