The average ACT score composite at Marquette University is a 27. The 25th percentile ACT score is 25, and the 75th percentile ACT score is 29. In other words, a 25 places you below average, while a 29 will move you up to above average.his school did not officially report its average GPA, but we've estimated it here using data from over 1,000 schools.). With a GPA of 3.65, Marquette University requires you to be above average in your high school class. You'll need a mix of A's and B's, with a leaning toward A's.