My Safari icon disappeared on my iphone 4s -- how do I get it back?

settings- general - reset home screen layout. Warning if you have apps in subfolder it will take it out and put it on the home screen.

You may have inadvertently moved it to another screen or placed it in a folder as it cannot be deleted as its a preinstalled app. Have a look on all screens and in folders if you've set them up. You can also search for it using spotlight. If you find it press and hold until the icon begins to wiggle and then drag it to the screen you want to place it on. Alternatively you can reset you home screen layout. Settings>General>Reset>Reset Home Screen Layout.

It could also have been hidden by restrictions (Settings>General>Restrictions) Or by a policy being enforced from an Exchange e-mail account (if you added your work e-mail to the phone, for example).

If the former case, turn off the restriction. In the latter case, by your IT person a nice bottle of Single Malt Scotch Whisky (not the cheap stuff) and ask politely if they can change the policy.

I found that turning off the restrictions (Settings>General>Restrictions) did the job, but there was one more step.

Boot the phone...nothing showed 'til I booted and Safari popped up as though nothing had happened.