Frequent Tournaments:
Swift Second Saturdays: https://discord.gg/Y8MDr4M
InkForce: https://discord.gg/5ZzpnyS
Bleck N Spoon: https://discord.gg/mvpcVYh
Casual Fridays: https://discord.gg/FV48HYY
Seascraper: https://discord.gg/uawRXjY
Major Tournaments:
SQSS: https://discord.gg/MxvMXdJ
EndGameTV Tournaments (Mostly LANs): http://discord.io/EndGameTV
Luti (League): https://discord.gg/0dZpaQB1mwamDbBk
Entry Level Tournaments:
Squid Spawning Grounds: https://discord.gg/pxdrc9u
New Squid City: https://discord.gg/GvexvQh
Fresh Start Cup: https://discord.gg/c2rwXDX
Tournaments:
It's Dangerous to go Alone: https://discord.gg/qzRabHM
Off The Hook Showdown: https://discord.gg/vd9hkBp
CNS League: https://discord.gg/kZ6C68A
Sendou's Tournaments: https://discord.gg/TZ6N3q7
Inactive Tournaments:
RSH (on hiatus): https://discord.gg/5hCJKWm
Young Ink (on hiatus): https://discord.gg/tvKD3Rx
SCL (on hiatus): https://discord.io/SplatoonSCL
G7: https://discord.gg/9EhZPWd
Planeptune Cup: https://discord.gg/ENknaFt
Splatour of Goliath: https://discord.gg/y8kHQXW
Splatoon Premier League: https://discord.gg/JRcCvFv
Anti-Meta Mondays: https://discord.gg/mPgnsCF
Sniping The Competition: https://discord.gg/hgVqYky
Pear v Pear (2v2): https://discord.gg/4RdRJQ6
NNCL: https://discord.gg/zkFET2A
Saturday Morning Coffee: https://discord.gg/F8mpqq9
ESL Splatoon: https://discord.gg/sCMpdqV
Tide Pool: https://discord.gg/63v2ru
The Intertidal Zone: https://discord.gg/bkctGCW
Tail's Tournaments: https://discord.gg/fMvXH9r
Message Snek#9658 or Fuchsia#8801 on Discord for adding tournaments to this list