I want to use a 4D Systems OLED display with an ATmega32u4 based PCB. I'm still working on designing the PCB and have hit a problem. In the data sheet it says that one of the power supply pins for the display requires 13.5-14.5 volts (which is VDDh). The problem is I will be powering the ATmega32u4 from a lipo battery with a 3.3V regulator. How do I convert 3.3V to 14V? Would I need to use a boost converter?
You will need to use a boost convertor. For best efficiency, you'll want to use a dedicated boost IC, rather than spin your own. It's not the best in performance, but I like the LM3578 for use by inexperienced people. It's adjustable, and the output voltage is set through a pair of resistors. As long as you put a reasonable LC network (see the datasheet) on the output and use a Schottky diode, it will regulate. It's also available in a DIP package for easy prototyping.
What you will need is a Boost converter, to convert the voltage from 3.3V to 14V. There are ways of doing this with discrete components (which I'm not really qualified to comment on), but another alternative would be an all-in-one package, such as MEE1S0315DC, which can convert 2.9-3.6V to 15V (but only ~1W, ~60mA).
Looking at the datasheet for the OLED, that should be enough current, and the voltage can be dropped to ~14V with an inline diode (ie a 1N4001).
As others have said, you need a boost converter. For the best efficiency you want to go directly off of your battery voltage, not off of the 3.3V. Also, the 3.3V regulator might not be able to supply enough current. You could spin your own design with an existing chip like Matt suggested, but I've heard that even the circuit board layout is difficult for switched mode power supplies. It would probably be worth it if you are making your own board already and going into production, but for prototypes there are numerous boards available with adjustable output voltages. Mostly they're on sites like Ebay or Alibaba. None of them are "name brands" or anything, you're buying direct from the factory, but I've had pretty good experiences with them. Here's a few examples. You obviously want to make sure they cover your whole battery voltage range, can output the voltage you need, and have enough current capacity.