Here are a ton of Clan Name Ideas organized in alphabetical order! Feel free to submit your ideas in the comments!

---Canon Names---
LeopardClan
LionClan
RiverClan
ShadowClan
SkyClan
StarClan
ThunderClan
TigerClan
WindClan

---Name Ideas---
AcornClan
AntClan
AppleClan
AshClan
AspenClan
BadgerClan
BarkClan
BatClan
BearClan
BeeClan
BerryClan
BirdClan
BlackberryClan
BlackClan
BlizzardClan
BoulderClan
BrambleClan
CactusClan
CalmClan
CeaderClan
ClamClan
CliffClan
CloudClan
CloverClan
CowClan
CragClan
DaisyClan
DarkClan
DesertClan
DirtClan
DoveClan
DustClan
EagleClan
EchoClan
EggClan
EmberClan
FishClan
FireClan
FlameClan
FlowerClan
FogClan
FoxClan
ForestClan
FrostClan
FrozenClan
GemClan
GorgeClan
GrassClan
GustClan
HailClan
HawkClan
HiddenClan
HillClan
HollyClan
HoneyClan
HorseClan
IceClan
IcicleClan
IvyClan
JaggedClan
JayClan
JuniperClan
KelpClan
LeafClan
LightClan
LightningClan
LilacClan
MarshClan
MintClan
MistClan
MistyClan
MoonClan
MountainClan
MouseClan
MysteryClan
NewtClan
NightClan
NutClan
OakClan
OceanClan
OrchidClan
OtterClan
OwlClan
PebbleClan
PineClan
PoisonClan
PrairieClan
QuailClan
RabbitClan
RainClan
RaspberryClan
RavenClan
ReedClan
RobinClan
RockClan
RoseClan
RustClan
RyeClan
SandClan
ShadeClan
ShadowClan
ShrewClan
SnailClan
SnowClan
SootClan
SpiritClan
SproutClan
StoneClan
StormClan
StrawberryClan
SquirrelClan
SunClan
TallClan
ThornClan
TimberClan
TreeClan
TulipClan
TundraClan
TunnelClan
TurtleClan
ValleyClan
VioletClan
VineClan
VoidClan
VolcanoClan
WildClan
WillowClan
WolfClan
WoodClan
YakClan
YarrowClan
ZebraClan

More added whenever I feel like it!