Jack Ryan is an agent with the CIA.
[Note up front: This is the "same" Jack Ryan created by Tom Clancy back in 1984. It has its own entry from the original because the two creators of this television series version took Ryan in a considerably different path, different enough IMHO to warrant its own page. I would recommend to anyone interested that they check out the write-up I did on the original to see the differences as well as the similarities.]
Ryan is an analyst with the Agency, not a trained field officer or a handler. His work area is his desk at Langley and he is quite happy to sit in his chair and study reports that come in to intelligently come up with explanations for things that have just happened and reasonable predictions for what is likely to happen next. He has no inclination to leaving the safety of his cubicle; he had more than paid his dues as a decorated Marine while fighting in Afghanistan. To Ryan's thinking, though, those harrowing days are over ... up until he finds it absolutely necessary to reluctantly head back out into the wild. Once there, however, I think even he would eventually admit that he is still very, very good in the field, albeit a tad rusty at the beginning.
Ryan is in his late 30s (most likely) and is in a committed relationship - not yet marriage - with Dr. Cathy Mueller, a noted physician and expert in infectious diseases who is a frequent speaker at conferences as she is asked to represent the WHO.
Ryan has earned his Ph.D. since his Marine days so has the right to be addressed as Dr. Ryan but he tends to use that only when having to deal with people who would only listen to a authenticated expert. Otherwise, he is happy to be simply called Jack.
For all the mention above about his initial preference to stay inside at Langley, once Ryan gets forced to go outside, he really has trouble coming back in. Things are a whole lot more interesting and exciting out there, never minding the bullets and shrapnel that seem to constantly head his way.