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An acronym for “separates, intimates and ready-to-wear,” SIR equips the modern woman with effortlessly feminine staples. It's a brand born of wanderlust and a want for effortless style, so its pieces belong as much in a suitcase as in the everyday wardrobe.

Drawing inspiration from the Australian coast, best friends Nikki Campbell and Sophie Cootewhat started with an online-only capsule collection that has quickly grown into an expansive selection ranging from dresses to two-piece suiting. From beach to boardroom, SIR has you covered with a new standard in essentials.

56 products

    • NEW ARRIVAL
    • EXCLUSIVE
    Exclusive to Mytheresa – Celena ribbed-knit maxi dress | SIR available sizes
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    • NEW ARRIVAL
    • EXCLUSIVE
    Exclusive to Mytheresa – Floral cotton and silk crop top | SIR available sizes
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    • NEW ARRIVAL
    • EXCLUSIVE
    Exclusive to Mytheresa – Alena open-back linen maxi dress | SIR available sizes
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    • NEW ARRIVAL
    • EXCLUSIVE
    Exclusive to Mytheresa – Floral cotton and silk maxi skirt | SIR available sizes
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    • NEW ARRIVAL
    • EXCLUSIVE
    Exclusive to Mytheresa – Floral cotton and silk minidress | SIR available sizes
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    • NEW ARRIVAL
    • EXCLUSIVE
    Exclusive to Mytheresa – Linen crop top | SIR available sizes
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    • NEW ARRIVAL
    • EXCLUSIVE
    Exclusive to Mytheresa – Celena ribbed-knit maxi dress | SIR available sizes
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    • NEW ARRIVAL
    • EXCLUSIVE
    Exclusive to Mytheresa – High-rise linen maxi skirt | SIR available sizes
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    • NEW ARRIVAL
    • EXCLUSIVE
    Exclusive to Mytheresa – Puff-sleeve cotton and silk minidress | SIR available sizes
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    • NEW ARRIVAL
    • EXCLUSIVE
    Exclusive to Mytheresa – Floral cutout cotton and silk maxi dress | SIR available sizes
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  • Anja cotton midi dress | SIR available sizes
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  • Anje cotton and silk minidress | SIR available sizes
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    • EXCLUSIVE
    Exclusive to Mytheresa – Alexandre linen maxi dress | SIR available sizes
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  • Vilma cutout linen minidress | SIR available sizes
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  • Josephine cutout maxi dress | SIR available sizes
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  • Ilkin asymmetric cotton maxi dress | SIR available sizes
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    • EXCLUSIVE
    Exclusive to Mytheresa – Alexandre linen minidress | SIR available sizes
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  • Clemence maxi skirt | SIR
    SIR

    Clemence maxi skirt

    £ 328
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  • Willa lace-trim satin minidress | SIR available sizes
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  • Kelvin cutout maxi dress | SIR available sizes
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  • Vilma cutout linen maxi dress | SIR available sizes
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  • Ilkin asymmetric cotton maxi dress | SIR available sizes
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  • Alexandre cutout linen minidress | SIR available sizes
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  • Zuri knit shirt | SIR
    SIR

    Zuri knit shirt

    £ 251
    available sizes
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  • Maja cotton jacquard midi dress | SIR available sizes
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  • Devin polka-dot swimsuit | SIR available sizes
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  • Lilian linen and silk maxi dress | SIR available sizes
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  • Lilian linen and silk minidress | SIR available sizes
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  • Isobel ribbed-knit wrap midi dress | SIR available sizes
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  • Aries lace-trimmed silk gown | SIR available sizes
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  • Marco cotton-blend midi dress | SIR available sizes
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  • Margot polka-dot silk minidress | SIR available sizes
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  • Franc cotton and silk maxi dress | SIR available sizes
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  • Celia floral cotton and silk shirt | SIR available sizes
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  • Anje cotton and silk midi dress | SIR available sizes
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  • Willa lace-trimmed silk gown | SIR available sizes
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  • Zuri knit wide-leg pants | SIR available sizes
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  • Anja cotton-blend bralette | SIR available sizes
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  • Anja cotton-blend poplin midi skirt | SIR available sizes
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  • Clemence bustier top | SIR available sizes
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  • Celia floral wide-leg pants | SIR available sizes
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  • Marco crêpe bustier top | SIR available sizes
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  • Celia floral cutout midi dress | SIR available sizes
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  • Devin polka-dot bikini top | SIR available sizes
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  • Devin high-rise bikini bottoms | SIR available sizes
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  • Anja cotton midi dress | SIR available sizes
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  • Devin polka-dot bikini top | SIR available sizes
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  • Marco cotton-blend minidress | SIR available sizes
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  • Devin polka-dot bikini bottoms | SIR available sizes
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  • Enid printed triangle bikini top | SIR available sizes
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  • Enid printed bikini bottoms | SIR available sizes
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  • Alexandre floral linen midi dress | SIR available sizes
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  • Clemence high-rise shorts | SIR available sizes
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  • Celia cotton and silk midi dress | SIR
    SIR

    Celia cotton and silk midi dress

    £ 379
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    sold out

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    • EXCLUSIVE
    Exclusive to Mytheresa – Ingrid stretch-knit bodysuit | SIR available sizes
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  • Clemence vest | SIR
    SIR

    Clemence vest

    £ 243
    sold out
    sold out

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56 products