I recently ran across this dilemma and wished to solve it once-and-for-all:
Can a whole note be used when writing in 3/4 time?
Here is the reasoning:
A whole note has a duration of four beats; however, a measure in 3/4 time only has a maximum duration of three beats. Therefore, a whole note would be the wrong notation to use.
“Whole notes are indeed incorrect in 4/4 time and whatever sheet music you have that uses them is in error – or at least, not adhering to the standard typographical conventions. But for the record, whole rests are correct in 3/4 time. Or more precisely, the symbol used to indicate a whole rest is also used used for what is sometimes called a “measure rest” – a rest of the duration of the measure, regardless of the length of the measure.”
Marc Sabatella on Musescore forum
So, in short, can a whole note be used in 3/4 time?
No.
Use a dotted half note.
Albeit, one can use a whole rest in 3/4 time. A whole rest is perfectly acceptable in this instance.