Here are known sales for the Memorial Day Weekend. Please feel free to add to it in the comments. I manually approve all links.

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Llarowe- Any one item from the website is 49% off with code llarowespringchicken
One day only, from 12:01am MST on May 26th to 12:00am MST May 27th

Victorian Disco Cosmetics –25% off all items in the store with code MEMORIALDAY
All weekend, from May 25th to May 27th 11:59pm CST

MOI Mineral Cosmetics ~ 20% OFF everything in shop with code ( 20offsale ) Starts Saturday Morning May26th- Midnight Monday May28th Atlantic Time

Sally’s Beauty- 50% off of all red tag clearance products in store and online. Online use code 555100
May 25th – May 28th

For Goodness Grape-
Use coupon code STARTSUMMERTODAY to save 15% off on your entire order.

Cherry Culture- Enter code MDS12 for 20% off anything in the store.
Now thru May 28th

Moon Rabbit Cosmetics – 15% off using code JBLC15
Now thru 31st

Dorian + Dahl Perfumery
get 15% off! Use the code, SNAILSSILVOUSPLAIT when you go to checkout!
Now until Tuesday!

Evil Shades– Code YNOT20 for 20% your purchase!

Meow Cosmetics
20% Off – Code: AFewGoodCats

Cult Nails
Pre-Sale Fairy Tales Collection Event
Get all 5 colors for $40