Round Cut Lab Grown Diamond Engagement Rings

Timeless, brilliant and universally adored — a round cut engagement ring is a style icon perfect for those who treasure elegant, enduring beauty. With its symmetrical, 58-facet cut, the round cut’s sparkle is unmatched, making it the most versatile shape for a wide range of settings. Suitable for solitaires, halos, vintage and modern designs alike, a round cut engagement ring is a classic choice that will never go out of style.

At Cullen, every round cut ring is handcrafted in our Australian workshop using ethically sourced materials and lab grown gemstones. Explore the collection online or begin your journey in-store with a personalized design consultation — whatever the process, we're here to help you cherish your forever love with the ring of your dreams.

Cullen specializes in custom-made round cut engagement rings, handcrafted to mark one of life’s most meaningful moments in a style unique to your love.

Widely admired for their enduring beauty and timeless, brilliant sparkle, round cut rings are an exquisite option for those who value elegance, sophistication, and iconic design.

Whether you’re seeking a sparkling solitaire or a vintage-inspired halo , our experienced jewelers and knowledgeable client advisors will guide you through every step of the journey — from concept to completion.

Each ring is made in our Australian workshop using conflict-free and carbon-neutral lab-grown diamonds, as well as sustainable lab-grown moissanite or sapphires, so you can feel confident your ring is as ethical as it is exquisite to look at.

Need a little guidance? Don’t hesitate to contact us or book an in-person appointment with one of our friendly engagement ring specialists to begin exploring our collection of round cut engagement rings available to ship across the United States.

Worldwide Express Shipping No matter where you are in the world, your dream ring will go the distance. We proudly ship our wedding and engagement rings across the United States and internationally, ensuring your ready-to-ship engagement ring arrives safely and swiftly.

We offer free resizing on all engagement rings to ensure the perfect fit, whether you've chosen one of our ready-to-ship engagement rings or something uniquely your own.

Lifetime Warranty Our engagement rings are built to last a lifetime. Each piece is backed by our lifetime manufacturing warranty , giving you complete peace of mind.

Free Ring Customization From unique engagement ring designs to personalized band details, we offer complimentary customization so you can craft a ring that's truly one of a kind.

Handcrafted in Australia Every ring — including our ready-to-ship engagement rings — is designed and handcrafted in our Melbourne workshop with exceptional attention to detail.

Conflict-Free, Sustainable Materials We offer a variety of unique options — from ready-to-ship lab diamond engagement rings to sapphire engagement rings — all ethically lab grown and sustainably sourced.

Carbon Neutral & One Tree Planted Partner We offset the carbon footprint of every order and plant a tree for each ring sold, supporting global reforestation.

Custom Design Specialists Whether you're interested in solitaire oval engagement rings or striking emerald cut engagement rings , our team specializes in creating custom pieces that reflect your personal style.