Cities in Southern Spain -what order?

Amanda instead of heading to Cordoba first, make a B line to Seville after landing in Madrid.

Seville - 3 Nights (Jerez de la Frontera)

Ronda - 1 Night

Granada - 2 Nights (Day trip to Nerja)

Cordoba - 2 Nights

Madrid - 2 Nights (Day trip Toledo)

Amanda, if you go to Seville first, I suggest staying 4 nights instead of 3 nights. Firstly, you will suffer from jet lag when you arrive, and you will most likely arrive later in the day, so you won't have much time or energy for sightseeing on your arrival day. If you take a day trip to Jerez, you basically will have one full day in Seville. Seville is a gorgeous city architecturally with many important historical and cultural sights. IMO, I think you need 3 full days for seeing Seville properly. If you want to see Jerez, then you definitely need 4 nights in Seville: 2 full days for Seville and one day for Jerez.

Regarding Madrid, it depends on what you want to see and do. Do you like art? Madrid has some outstanding art museums, Palacio Real, San Miguel market, Retiro Park, etc. I really like Madrid although I know a lot of people don't. What time will you arrive in Madrid? You may only have 1/2 day in Madrid if you go to Toledo the next day. That's ok if you aren't interested in the art museums or the other sights I listed.

Instead of reading only itineraries, I think it is most helpful to read several good guidebooks, such as Rick's, Michelin Green Guides, Rough Guides, Lonely Planet. Only you can decide what is important to you.

I disagree with some of RJean's suggested time allocations/day-trip plans.

Three nights in Seville will give you just two days (not counting a few jetlagged, sleep-deprived hours on your arrival day), and the day-trip to Jerez will chew up most of one of them. Seville is a large city with a lot of interesting sights; it deserves a lot more time than that. I'd consider three nights without a side-trip to be the absolute minimum.

Two nights in Granada would give you less than 1-1/2 days by the time you get there from Ronda and get settled in. If you take a day-trip to Nerja (Google for water-quality issues at the beach), when are you going to see Granada? The Alhambra alone can consume the better part of a day.

There's fast rail service from Seville to Granada (though not many trains per day at this point). Inserting Ronda between those two cities will probably at least double the amount of time you have to spend on trains and/or buses. Although I like Ronda, I'm not sure it's worth that extra transportation time when you have so few days to work with. You might like to use the Ronda day and the saved 3 hours of extra transportation time in Madrid, Seville or Toledo.

I think we’ll definitely head to Seville first. I haven’t considered daytripping to Jerez yet, I’ll look into that. We’re not interested in beaches so not worrying about Nerja.
But I do want to try and squeeze Ronda in! I’ll keep checking into bus and train routes.
Sorry, I didn’t mention we spent plenty of time in Madrid on a previous trip so we’re just focusing on Andalusia this time around. Just flying in/out of Madrid in very cheap tickets.
Thanks for the advice!

Since you seem to be in Madrid only as a convenience, how about going to Toledo either at the beginning or the end of the trip? The ideas below assume you must spend your last night in Madrid because of a morning flight home. If your flight is later, you could go to MAD straight from Toledo (worst case - train/bus strikes and have to pay for a taxi to the airport). Toledo is much better as an overnight so you have some morning and evening time without the daytrippers, instead of being them.

Going at the beginning - short train ride, but arriving zonked. If you do that, you could either stay 1N and take a late train to Cordoba (just because it's a shorter train ride than Sevilla), or stay 2N and take an early train. It doesn't really matter which order you go to Cordoba and Sevilla, in the end, same travel time.

Going at the end, you have your choice of taking an early train to Toledo, and/or a late train to Madrid, so you can decide pretty much last minute where you want to spend more hours. While tickets often sell out on the day, if you buy a day or 2 ahead, you shouldn't have a problem. You can also store your bags at Atocha and just take a small overnight bag to Toledo.

Just to pile on, how about skipping Ronda and taking a little more time to enjoy the other towns? That would allow you to daytrip to Jerez/Cadiz or even Jerez/Arcos from Sevilla. OR add a night to Toledo.