An underlying plot point that reappears every so often in Arrow is that out there in The CW’s DC TV Universe Oliver Queen has a son. However, Greg Berlanti’s style of writing often includes dramatic irony, this being that the audience knows what is going on but the main character doesn’t. We know Oliver Queen has a child before he does. It isn’t really a present storyline as it only rears its head very occasionally to remind us that the kid is out there. It’s not an issue that is explored at all really, it is just known. The idea of Oliver having an estranged child was first posed in season 2 in a flashback scene. The scene consisted of Oliver’s then girlfriend telling his mother that she was pregnant. Moira Queen paid the woman millions of dollars to leave town without telling anyone that she was pregnant. The same woman bumps into Oliver in Central City at the end of the ‘Flash Vs Arrow’ crossover episode. In that scene the main characters exit leaving the woman in the cafe on the phone to Oliver’s son.

In an interview with Screen Rant Amell has said that viewers would get to see Oliver meet his son some time in Arrow’s future. Amell also said that it is a storyline he would personally like to see explored. In the interview with he had this to say:

“Me personally being a dad, I would love to see how Oliver interacts with having a kid. Obviously, it would be a different experience from that experience, but I think that storyline deserves further attention. One of the big tenants of Greg Berlanti is you don’t introduce something to the audience, you don’t tease it if you are not going to follow through with it (in) some shape or form. So I think it’s a safe bet that Oliver will find out about his child at some point.” 

Green Arrow does have a long-lost son, however he doesn’t meet him when he is an adult, I doubt the series would wait that long to introduce the character, it would have to run for a long time for that to happen, I mean we are talking a run similar to Cheers. Which is unlikely to say the least. Personally I think we can expect to see Arrow meet his son some time in the next couple of seasons. But remember, knowing what Berlanti is like Oliver may meet his son but that doesn’t necessarily mean that he knows that he is his father at the time.