Dublin to London Flights

Depends. Assuming your flight arrives in Dublin on time (i never assume) - will you already have your Ryan Air boarding pass? Will you be carry on only? If you answer no to either of those, you wont be able to stay airside, but will have to leave the secure area to check in. Which could make it tight getting to your connecting gate. The good news is if you miss the flight, you should have no trouble buying a ticket on one of the frequent flights later in the day.

Thank you! We have carry-on bags and we already have our boarding passes. But I wasn't sure what sort of international security or customs we would have to pass through (if any) before continuing on to London. The next flight isn't for several hours later - so I would rather make this 11:15am flight, but it does seem rather tight.

This is our first time traveling through Dublin to London -- so I'm not too sure what to expect. Thank you!

You will need to go through Irish immigration when making any connection to the UK because they have a common travel area with the UK; you'll be inspected and stamped in there rather than on arrival in London. I don't know if there will be any other complications based on your connection being a separate Ryanair ticket as my trips through Dublin have all been single ticket direct connections on Aer Lingus. Irish immigration has been pretty quick and efficient in my experience. If your flight from the US was just to Dublin (i.e., not through ticketed to London) then that airline probably didn't check whether you have your UK ETA, but someone will be checking that in Dublin, either Irish immigration and/or Ryanair. They should have access to an electronic record of it but always a good idea to carry your confirmation of your ETA on paper and/or accessible on your phone.

Because you are flying into the Common Travel Area with the UK I’m pretty sure you will need to clear immigration at DUB whether you have checked bags or not.

Read the advice about I am a non EU citizen and need to complete a visa check on this page

https://help.ryanair.com/hc/en-gb/sections/12488903024145-Travel-Documents

Ryanair have their own policy about checking documents, so make sure you comply with whatever applies to you

As stated, you will be going through Irish immigration upon arrival in Dublin. This gives you permission to enter both Ireland and the UK (for up to three months instead of the six you get arriving directly into the UK.)

You should have enough time. Just check on whether both flights are in the same terminal. Follow Ryanair's check in rules exactly otherwise you could be charged extra.

Upon arriving at Gatwick, you will just walk off the plane and go about your business. Just like a domestic flight in the US.

There is no EES in Dublin as it is not Schengen. You will need an ETA to enter the UK.