As Catholic historian Matthew Bunson notes, we know very little about Simon of Cyrene, aside from several passages in Scripture (Matt. 27:32; Mark 15:21; Luke 23:26), and there is no tradition of his being honored as a saint.
Of course, he is known for helping Jesus carry his cross to Calvary and thus has an honored place in salvation history. But just because the Church hasn’t formally recognized someone as a saint doesn’t mean that person isn’t in heaven and thus a saint. That’s the eternal bottom line for which we all strive—attaining heaven while not necessarily making it onto the Church calendar.