Here you'll find a list of all the moves that Greninja can learn either by leveling up or by using TM's and HM's. Please note that this list only covers moves it can learn in Pokémon X/Y.

Moves learned by leveling up:
Level: Move: Type: Category:
-- Night Slash Dark Physical
-- Role Play Psychic Status
-- Mat Block Fighting Status
-- Pound Normal Physical
-- Growl Normal Status
5 Bubble Water Special
8 Quick Attack Normal Physical
10 Lick Ghost Physical
14 Water Pulse Water Special
20 Smokescreen Normal Status
23 Shadow Sneak Ghost Physical
28 Spikes Ground Status
33 Feint Attack Dark Physical
36 Water Shuriken Water Physical
43 Substitute Normal Status
49 Extrasensory Psychic Special
52 Double Team Normal Status
56 Haze Ice Status
60 Hydro Pump Water Special
70 Night Slash Dark Physical
75 Water Shuriken Water Physical

Moves learned by TM/HM:
TM/HM: Move: Type: Category:
TM06 Toxic Poison Status
TM10 Hidden Power Normal Special
TM12 Taunt Dark Status
TM13 Ice Beam Ice Special
TM14 Blizzard Ice Special
TM15 Hyper Beam Normal Special
TM17 Protect Normal Status
TM18 Rain Dance Water Status
TM21 Frustration Normal Physical
TM23 Smack Down Rock Physical
TM27 Return Normal Physical
TM28 Dig Ground Physical
TM32 Double Team Normal Status
TM39 Rock Tomb Rock Physical
TM40 Aerial Ace Flying Physical
TM42 Facade Normal Physical
TM44 Rest Psychic Status
TM45 Attract Normal Status
TM46 Thief Dark Physical
TM48 Round Normal Special
TM49 Echoed Voice Normal Special
TM55 Scald Water Special
TM56 Fling Dark Physical
TM62 Acrobatics Flying Physical
TM68 Giga Impact Normal Physical
TM80 Rock Slide Rock Physical
TM86 Grass Knot Grass Special
TM87 Swagger Normal Status
TM88 Sleep Talk Normal Status
TM89 U-turn Bug Physical
TM90 Substitute Normal Status
TM94 Rock Smash Fighting Physical
TM97 Dark Pulse Dark Special
TM98 Power-Up Punch Fighting Physical
TM100 Confide Normal Status
HM01 Cut Normal Physical
HM03 Surf Water Special
HM04 Strength Normal Physical
HM05 Waterfall Water Physical