The two YouTube sensations - who had previously fought against one another in white collar and professional boxing matches - teamed up to create PRIME in January.
Following news of Arsenal's hydration partnership with PRIME, the drink will now be available for fans to purchase on matchdays at the Emirates Stadium.
Boyhood Gunners fan KSI told arsenal.com: "Honestly, I can't believe it, this is a childhood dream of mine. From watching Arsenal tear up the Premier League in the early 2000s to now being associated with Arsenal officially with PRIME, it's a dream come true and I'm still pinching myself! This is a huge moment and I'm so glad it's with the team I support."
Chief Commercial Officer Juliet Slot added: "We are always looking to join forces with new, exciting and forward-thinking brands. PRIME falls comfortably into that category, with a product and founders at the forefront of modern culture.
"KSI is a lifelong Arsenal supporter and it's fantastic we can keep this in the family. I'm sure our supporters will love the drink and I'm excited to see the fun ways we will bring this partnership to life."
Mikel Arteta's side return to their North London home for their final pre-season game on Saturday, as Sevilla tackle the Gunners in the Emirates Cup.
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