This product is the reason you'll never see Sienna Miller with frizzy hair

There is plenty to envy when it comes to Sienna Miller, but her gorgeously smooth blonde hair has to rank high on that list. Her secret? A hard-working cream that will cost you less than £30...

Avoiding frizz can feel like an impossible task, particularly in wet autumnal weather, and even some of the best hair oils on the market can't be relied on to keep flyaways and hard-to-tame tresses at bay throughout jam-packed days.

Thankfully, celebrity hairstylist Sam McKnight has revealed exactly how he gives Sienna Miller her signature soft waves, and the answer couldn't be simpler. Whether you want to know how to get healthier hair or you're desperate to get your ends as sleek as Sienna's, you'll want this miracle cream in your arsenal.

Hair by Sam Mcknight Dressed to Kill 50ml

Designed to control, define, and nourish, this cream softens and conditions hair whilst adding light hold that will keep frizz and flyaways under control. With the hydration of an oil without any greasiness, it's the ultimate styling product that will boost shine and keep hair in place.

McKnight told British Vogue he kept Sienna's hair "defined and frizz-free with my Dressed to Kill cream," for the Chloé runway show earlier this year, and it's clear from her incredible beachy waves at the event that it did just the trick.

We're sure that regular hair treatments and brilliant heat styling by top hairdressers are to thank too, but Sam McKnight products are easily some of the best on the market for fuss-free and effective styling - and the results speak for themselves.

Sienna has had her hair styled by Sam McKnight on countless occasions, so it's clear she is a fan of the brand. We can't say we've ever seen her hair look less than perfect, and if we can get similarly frizz-free and conditioned locks for just £26, we're on board.

Shop more Hair by Sam McKnight

Hair by Sam Mcknight Bigger Love Treatment Mask 200ml

Yes, it's on the pricey side, but this is one of the best hair masks if your hair is in desperate need of repair. Formulated with dual-acting voluminis™ that visibly thicken the hair, it will make hair stronger and more volumised.

Hair by Sam Mcknight Love Me Do Nourishing Oil 50ml

If you find hair oils tend to be too heavy for your hair, this is the one to try. It has a water-like consistency that hydrates without weighing the hair down or leaving a greasy residue.

Hair by Sam Mcknight Lazy Girl Biodegradable Hair Cleanse Cloths 100g

If you find yourself frequently relying on dry shampoo but hate how itchy it makes your scalp, you need to try these wipes. You use them to cleanse your roots and follow up with a very quick blow dry and your hair looks freshly washed - a true miracle product.