Are you flying on one ticket? If so, then Ryanair would be responsible for making sure there was enough time to make the connection. You will have to clear security to catch your connecting flight.

no those are 2 different tickets, shouldn't have mentioned connecting flight in subject line

Ryanair does NOT do connecting flights precisely to not have any responsibility in that area. This is a very close connection as you will have to EXIT, go to their ticket desk, wait in line if there is one, and then re-enter security and find gate. Fortunately T1 is smaller than T4 but this is going to be tough. Could they stamp your boarding pass in Brussels? Not sure if they do that there.

And is Ryanair still asking people to get that stamp in Spain? We are all hoping that obligation disappears at some point but if it says so on your ticket, it hasn't yet.

Two separate tickets on ANY airline with only one hour between flights for ME would be VERY stressful.

there's an aireuropa flight at 22.20 pm for 50 euros I think i would book in case you miss your flight. small investment. same terminal.
go to www.lastminute.com to see all possibilities.

Check with Ryan air to see how long before light time the gate closes for your Ibiza flight. They do not give you a minutes leaway. I've seen them close it with people standing in line, so this won't be fun, even if you do make it.

I wouldn't dare attempt a one hour connection flying on 2 tickets. You're bound to miss the connection and the airlines will be under no obligation.

If you do do this, my advise would be to get priority boarding for your first flight. And make sure you sit close to the front exit door as possible. If in Madrid, they use busses to ferry passengers from the plane to the terminal, again, make sure you are standing close to the bus exit doors.

One thing in your advantage: the low costs don't waste any time filling up and unloading planes. I also suspect that Ryan Air flights typically land twenty minutes earlier then advertised. So even if their flights are delayed, this 20 minute buffer ensures that they they can keep their claim that over 90% of their flights arrive on time.

If all goes like clockwork, it's possible. But a delay anywhere may cost you your flight.

Thanks everyone for their valuable suggestions.
I got on call with Ryan air and as it turns out I'am not legally authorized to board another Ryan air flight till another 2 hours of my first flight landing.
So there goes my 45 euros for total waste. I will be looking for another alternative now.

Folks, please take note that Ryan air rules doesn't allow you to board another flight within a span of 2 hours!!