One of Photoshop's key features is that almost everything in it can be controlled using keyboard shortcuts. This allows the user to stay in a creative thought pattern and quickly change tools in monotonous work that requires it.

Main Toolbar
Key	Action	Action	Key
m	Marquee Tool	Move Tool	v
l	Lasso Tool	Magic Wand Tool	w
j	Airbrush Tool	Paintbrush Tool	b
s	Rubber Stamp Tool	History Brush Tool	y
e	Eraser Tool	Pencil Tool	n
r	Blur Tool	Dodge Tool	o
p	Pen Tool	Type Tool	t
u	Measure Tool	Linear Gradient Tool	g
k	Paint Bucket Tool	Eyedropper Tool	i
h	Hand Tool	Zoom Tool	z
d	Default foreground and background colors.
x	Switches between foreground and background colors.
q	Switches between standard mode or quick mask mode.
f	Switches between screen modes.
TAB	Hides/Unhides open tools.

File Menu
Key	Action
CTRL + N	New
CTRL + O	Open
CTRL + ALT + O	Open As
CTRL + W	Close
CTRL + S	Save
CTRL + SHIFT + S	Save As
CTRL + ALT + S	Save a Copy
CTRL + SHIFT + P	Page Setup
CTRL + P	Print
CTRL + K	Preferences > General

Edit Menu
Key	Action
CTRL + Z	Undo
CTRL + X	Cut
CTRL + C	Copy
CTRL + SHIFT + C	Copy Merged
CTRL + V	Paste
CTRL + SHIFT + V	Paste Into
CTRL + T	Free Transform
CTRL + SHIFT + T	Transform > Again

Image Menu
Key	Action
CTRL + L	Adjust > Levels
CTRL + SHIFT + L	Adjust > Auto Levels
CTRL + ALT + SHIFT + L	Adjust > Auto Contrast
CTRL + M	Adjust > Curves
CTRL + B	Adjust > Color Balance
CTRL + U	Adjust > Hue/Saturation
CTRL + SHIFT + U	Adjust > Desaturate
CTRL + I	Adjust > Invert
CTRL + ALT + X	Extract

Layer Menu
Key	Action
CTRL + SHIFT + N	New > Layer
CTRL + J	New > Layer Via Copy
CTRL + SHIFT + J	New > Layer Via Cut
CTRL + G	Group with Previous
CTRL + SHIFT + G	Ungroup
CTRL + SHIFT + ]	Arrange > Bring to Front
CTRL + ]	Arrange > Bring Forward
CTRL + [	Arrange > Send Backward
CTRL + SHIFT + [	Arrange > Send to Back
CTRL + E	Merge Down
CTRL + SHIFT + E	Merge Visible

Select Menu
Key	Action
CTRL + A	All
CTRL + D	Deselect
CTRL + SHIFT + D	Reselect
CTRL + SHIFT + I	Inverse
CTRL + ALT + D	Feather

Filter Menu
Key	Action
CTRL + F	Last Filter
CTRL + SHIFT + F	Fade

View Menu
Key	Action
CTRL + Y	Preview > CMYK
CTRL + SHIFT + Y	Gamut Warning
CTRL + +	Zoom In
CTRL + -	Zoom Out
CTRL + 0	Fit on Screen
CTRL + SHIFT + 0	Actual Pixels
CTRL + H	Hide Edges
CTRL + SHIFT + H	Hide Path
CTRL + R	Show Rulers
CTRL + ;	Hide Guides
CTRL + SHIFT + ;	Snap To Guides
CTRL + ALT + ;	Lock Guides
CTRL + "	Show Grid
CTRL + SHIFT + "	Snap To Grid

Help Menu
Key	Action
F1	Contents

Other Shortcuts
Key	Action
Page Up/Down	Move view up/down 1 screen.
SHIFT + Page Up/Down	Nudge view up/down.
CTRL + Page Up/Down	Move view left/right 1 screen.
CTRL + SHIFT + Page Up/Down	Nudge screen left/right.
CTRL + SHIFT + Z	Previous History entry.
CTRL + ALT + Z	Next History entry.
SHIFT + -	Previous blending mode.
SHIFT + +	Next blending mode.