Is there any flag that can be flown over the U.S. flag?

If the flags of other nations are displayed with the American Flag, they should be of equal size and at equal heights on separate staffs at a time of peace. The American Flag ... If a state, local or society flags are flown on the same halyard with the American Flag, the American Flag should be at the top. read more

It depends if you mean allowed to or whether it is customary to do so. If you mean customary to do so, then it is customary to fly national flags (and flags of former nation states) at the same level, out of respect. read more

*Army Regulation 840-10 2-2.c, reads, "The flag of the United States is the only flag that may be flown from a flagpole over a CONUS Army installation unless an exception is granted by TIOH, U.S. Army. read more