Is there a 16 to 4 one-hot simple encoder IC chip?
The function you are looking for is normally referred to as a Priority Encoder.
A priority encoder can cope with more than one signal being active and still give the correct result for the highest numbered active input. If your system can guarantee that one and one input only will be active you can use a simpler solution as suggested by Dave Tweed in the comments, however such solutions can give a completely incorrect result if two or more inputs are active.
As far as I know there has never been an off-the-shelf device to implement a 16-input priority encoder.
An 8-bit version has been around for many years.  One of the current versions is SN74HC148.
@Marku points out that the data sheet (link above) has a 16-bit example using two such devices together with 4x 2-input AND gates requiring three packages in total.
These days it is more common to implement functionality like this either in software within a microcontroller or in programmable hardware in Verilog/VHDL.
Can you describe your system in more detail to see which solution would fit better?