When it comes to building a successful Shopify store, your theme can make or break the customer experience. From clean design to seamless functionality, the right agency can help you create a storefront that not only looks great but also drives conversions.

In this article, we highlight the top Shopify theme design agencies that specialize in crafting custom themes and solutions tailored to your brand. Whether you’re launching your first store or scaling to Shopify Plus, these experts combine creativity and technical skill to help your business stand out in the crowded eCommerce landscape.

Best Shopify Theme Design and Development Agencies

1. Realm

Realm is a full-service Shopify agency started by one of Shopify’s first experts. Since 2012, they have built successful stores for Fortune 500s, start-ups and Shopify Plus. They’re known for their Shopify expertise, pixel perfect aesthetics and an in-depth understating of visitor’s shopping experience. Because of their proven track record of increasing sales, ROAS and delivering the best ROI for their clients, they are one of the most sought-after Shopify agencies.

Realm has worked with over 250+ brands and have established an impressive reputation with countless 5-star reviews. When you work with Realm, you can expect top-notch service and a dedication to the success of your brand backed by support for the years to come.

• Services and expertise: Shopify store set‑up & migrations, Shopify POS, custom theme design, app development, Shopify SEO, content writing, digital marketing (Facebook, Instagram, Email/SMS, Google), Shopify Plus enterprise, conversion optimization and ongoing support.
• Team size: 2-10 employees
• Location: headquartered in the United States, operating globally
• Clients: SYLTBAR, Byers’ Choice LTD, Lash & Wax OC, Freewaters, zkano, CoolSnowGlobes, Sunrise Flour Mill and more.

2. Avex

Avex is an award‑winning Shopify Plus agency delivering unified commerce experiences for enterprise and high-growth brands. With over a decade of industry leadership, their strategic, design-first approach spans DTC, B2B, and retail, combining UX/UI design, headless commerce, CRO, and email/SMS marketing to provide the best Shopify app development services.

Their team is known for attentive collaboration, thoughtful problem-solving, and delivering outcomes that resonate with both brands and their customers. By bridging creative vision and technical execution, Avex supports brands in building meaningful connections and driving long-term success online.

• Services and expertise: Shopify Plus migrations, UX/UI design systems, headless commerce (Hydrogen/Oxygen), CRO/A‑B testing, email & SMS marketing (Klaviyo), B2B/DTC/retail unification
• Team size: 11-50 employees
• Location: headquartered in New York, with global remote talent
• Clients: Hugo Boss, quip, AriZona Beverages, Equinox, TAG Heuer, KITH, FILA, Simmons Bedding, Calvin Klein, Tru Earth, and more

3. WebDesk Solution

WebDesk Solution is a North American digital agency turning eCommerce goals into reality with expert design, development, and AI-driven innovation. With 13+ years of experience and 500+ clients, they craft tailored platforms, from headless commerce to web and mobile apps focused on speed, UX, and seamless integrations. Recognized as one of the best Shopify design agencies, they’re certified partners with Shopify and BigCommerce, delivering high-performance solutions through agile processes and thorough discovery.

Known for award-winning designs and attentive post-launch care, WebDesk helps brands stay competitive with data-driven strategies, advanced conversion tracking, and measurable growth in fast-changing markets.

• Services and expertise: eCommerce consulting, Shopify & BigCommerce migrations, custom web/mobile development, headless commerce, UI/UX design, CRO, conversion tracking & speed optimization, AI/chatbot integration, digital marketing
• Team size: 8–20 employees
• Location: Toronto, Canada & Great Neck, New York, USA
• Clients: 500+ North American clients including TELUS, Intelcom, Surplus Furniture, One Tree Planted, Camera Source

4. Evestar

Evestar is a North American agency that is among the top Shopify theme design agencies. Founded by entrepreneur Lolita Petrossov, the team applies design‑focused and data‑driven strategies across creative, development, and marketing disciplines. They have supported over 200 brands in increasing revenue and conversion rates through thoughtful optimization and testing.

Clients report significant improvements, such as doubling online revenue within months and achieving 600–700% ROAS on campaigns. Known for collaborative workflows and attention to detail, Evestar helps brands make informed decisions and strengthen their digital presence in a competitive eCommerce landscape.

• Services and expertise: Shopify & Shopify Plus development, custom theme and app builds, migrations, CRO, performance marketing (Facebook/Google/TikTok, email/SMS automation), SEO, UI/UX, paid social creative, headless solutions
• Team size: 50-249 employees
• Location: headquartered in the United States, operating globally
• Clients: Wellgenix, Currus, Fawn, Imperia, Nood

5. Swanky

Swanky is a full-service Shopify Plus agency operating across the UK, Australia, and France. Since 2010, they’ve focused exclusively on Shopify, earning “Shopify Plus Expert” accreditation in 2016 and achieving Platinum Partner status in 2025. Their team blends design, development, data analysis, and strategy to tackle complex eCommerce challenges like subscription models, international expansion, and composable commerce setups.

Trusted by mid-market and enterprise brands, Swanky emphasizes a test-and-learn approach, reportedly achieving up to 60% CRO win rates and supports long-term growth through continuous optimisation and full-funnel marketing.

• Services and expertise: Shopify Plus migrations, custom theme & app development, composable & headless commerce, conversion rate optimisation (CRO), analytics, subscription site builds, digital marketing, internationalisation
• Team size: 50-200 employees
• Location: Exeter (UK), offices in Australia & France, serving global clients
• Clients: HelloFresh (Japan launch), daysoft®, Medley Jewellery, Fishpools, Natural Instinct, Catit, Eden Project, Wilkinson Sword

6. Electric Eye

Electric Eye, founded in 2016 in Columbus, Ohio, provides custom Shopify theme development and optimization for direct-to-consumer lifestyle brands. With over 100 Shopify stores delivered, their team focuses on mobile-first design, speed improvements, UX/UI enhancements, and conversions through diagnostics, A/B testing, and landing page optimization.

Clients highlight Electric Eye’s clear communication, reliability, and ability to simplify complex migrations and technical challenges. By combining data-informed insights with a consultative approach, they support brands in building polished, performant storefronts that resonate with customers and reduce operational friction.

• Services and expertise: Custom Shopify theme & app development, migrations (Matrixify experts), optimization & maintenance retainers, diagnostics, UX/UI, CRO, page speed, landing pages, A/B and user testing, eCommerce strategy
• Team size: 2-10 employees
• Location: Ohio, USA, operating worldwide
• Clients: Sheec, Marley Fragrance, Broccoli, Rancho Gordo, Pocket Hose, Barton Perreira

7. Diff Agency

Diff Agency is a full-service commerce consultancy and Shopify Plus Partner known for engineering high-performance online stores. With a track record of over 15 major brands, they deliver tailored solutions spanning custom theme development, app integration, and UX optimization.

Their collaborative, data-led approach shows results like a 430% sales increase for a DTC bedding brand and significant operational savings for Canadian fashion retailer Rudsak, where they helped save over 5,410 hours annually. Diff also hosts industry events such as “Constructing CX” in partnership with Shopify to explore advanced customer-experience systems.

• Services and expertise: Custom Shopify Plus theme & app development, UX/UI design, integration & headless commerce, conversion optimisation, QA, digital analytics, omnichannel strategy
• Team size: 100-150 employees
• Location: headquarters in Montreal, with additional operations in San Francisco and Toronto
• Clients: Tommy John, Fashion Nova, PopSockets, Boll & Branch, Rudsak, Tonies, Lionsgate, Bouclair, Sakara, Hill’s Pet Nutrition

8. The Working Party

Founded in 2011, The Working Party has become one of the best Shopify design and development agencies. They’ve led Shopify Plus launches for major retailers like JB Hi‑Fi, KOOKAÏ, Assembly Label, Lovisa, and New Era, applying their proprietary Growth Framework to deliver design-driven, data-led eCommerce solutions.

Leveraging retail-industry insights, the agency manages full lifecycle projects, including migrations from platforms like Magento, Salesforce, and Hybris while supporting ongoing optimization and international growth. Their disciplined, client-focused approach underpins successful case studies where brands continue to evolve post-launch.

• Services and expertise: Shopify Plus design & development, migrations, growth framework (CX, SEO, performance, analytics), integrations, composable/headless commerce, internationalisation, subscription/omnichannel strategy
• Team size: 11-50 employees
• Location: Hawthorn, Victoria, Australia (offices in Melbourne and Sydney)
• Clients: JB Hi‑Fi, KOOKAÏ, Assembly Label, Lovisa, New Era, Mister Zimi, Sheike, Farmers Pick, Deus ex Machina, CSD Brands

9. Underwaterpistol

Underwaterpistol is a UK-based Shopify Plus agency operating from London since 2003. With over two decades of experience, they’ve completed more than 200 projects in-house across industries like fashion, food and drink, and home goods. Their in-house team covers everything from creative design to technical development, with a structured four‑phase framework focused on planning, building, growing, and accelerating eCommerce success.

Known for a test-driven, data-led approach, Underwaterpistol has delivered outcomes such as improved customer loyalty tools and smoother platform migrations for clients. Recognised by many as a best Shopify app development company, they’re valued for solving complex eCommerce challenges through integrations, customised apps, and ongoing optimisation support.

• Services and expertise: Shopify Plus design & development, custom app development, theme design, UX/UI, subscriptions & loyalty programs, SEO, CRO, platform migrations, internationalisation, analytics & optimisation
• Team size: 11-50 employees
• Location: headquartered in London, operating globally
• Clients: Ooni, Omaze, Reach PLC, Candy Kittens, NEOM Organics, Biscuiteers

10. Arctic Grey

Arctic Grey is an award‑winning Shopify Plus agency that supports enterprise-level merchants across North America and Europe. They’ve worked on over 1,000 Shopify stores, helping generate upwards of $1.5 billion in client revenue and earning more than 550 five‑star reviews and 28 commerce awards. Their team blends design, development, and performance optimisation, specialising in mobile-first UX, custom theme work, migrations, and speed improvements.

Through data-led work such as a 30% lift in conversion within one month for a jewellery retailer and a 22% increase for a beauty brand, Arctic Grey demonstrates measurable impact . Their structured, full‑lifecycle approach aims to support long-term ecommerce growth while keeping stores stable and scalable.

• Services and expertise: Custom Shopify Plus theme & app development, enterprise migrations (Magento/WooCommerce/Salesforce), UX/UI design, mobile-first optimisation, Shopify theme customization services, performance tuning, conversions, QA, headless/composable commerce, analytics
• Team size: 80+ employees
• Location: Silicon Valley HQ, offices in Los Angeles, New York, Chicago, Seattle, Toronto, Boston, London
• Clients: Ipsy, Olaplex, Peanuts, Botany Farms, Ken & Dana, Headbanger Sports, Goodwynns, Albee Baby, and other enterprise brands

Conclusion

Choosing the right partner for your Shopify store can make all the difference in creating a seamless shopping experience and driving growth. The agencies highlighted in this article bring the creativity, technical expertise, and strategic insight needed to help your brand succeed online.

If you’re ready to elevate your store with a custom theme, app, or full-scale eCommerce solution, don’t hesitate to hire Shopify expert developers who can turn your vision into a high-performing reality. With the right team by your side, your Shopify store can stand out and thrive in today’s competitive market.

If you’re a Shopify Theme Design agency and want to feature your company on this list, email us with details or submit this form. After a quick evaluation, we’ll define whether it’s a valuable addition.