First time London (w/ young kids!) is this a good itinerary??

I remember loving a visit to Kew Gardens when I was nine.

Overall sounds like a good plan, well thought out. Just a few comments.

Paddington - not that central and a little run down (you will need to take the tube a lot), but perfectly fine - it does have some good and cheap places to eat. Hyde Park is lovely, and especially good with kids. Alternatively for a similar price range there are lots of cheap hotels around King's Cross Station. More central but much pricier are areas in the west end like Covent Garden, St James', Mayfair, and Belgravia.

Getting there from the airport - Heathrow Express is the most expensive options. Tube is substantially cheaper - you will have no problem with bags as the Piccadilly Line originates at Heathrow, so you'll be first on. Alternatively, take the Elizabeth Line to Paddington - it's almost as fast as the Heathrow Express and much cheaper. Just use your contactless card to pay.

Museums - I definitely recommend the Young V&A at Bethnal Green - it's great for kids. The Natural History Museum in South Kensington is also awesome for young ones.

Day 4 - Oxford Street is not what it once was - it looks really sad and run down. I would recommend Regent Street (which is nearby). For upmarket department stores, try Fortnum & Mason and Liberty. Harrods is in South Kensington, so nowhere near - it is however close to the Science Museum, Natural History Museum etc, so maybe club it together on that day. The area around South Kensington and Chelsea also has lots of nice smaller shops.

Day 8 has me confused - why stay near Heathrow? I would advise just staying in Central London and heading to the airport on the day of your flight. Windsor is an easy half day from London.

Other royal places not to be missed - Tower of London. Probably Kensington Palace as well (although not everyone loves it, including the people for live there!). On day 5, you could probably add a walk past St James' Palace (home to some minor royals, and the oldest working royal palace). Also have a walk through St James Park and across to Horse Guards, where you can see the changing of the King's Life Guard up close. These are troops of the Household Cavalry Regiment.

Highclere Castle is easy to get to by train from London, plus a short taxi trip to/from the nearest station. But I'm not sure how interesting it would be for kids. Also easy to get to by train from London and more impressive is Hatfield House, residence of the Marquess of Salisbury - check the opening dates as it's only open for a limited period in summer. There's also Woburn Abbey, residence of the Duke of Bedford (he has the largest art collection in private hands in the UK apart from the King).

Lots of great pubs in London, not a lot of space for patios - in summer it will mainly be drinkers standing on the footpath outside with a beer in hand. Country pubs tend to be the ones with beer gardens and outdoor dining.

The PI at Paddington is the newly developed Paddington Basin area with a lot of apartments, offices, restaurants and shops so it could be quite convenient for a young family. The canal is right there for pleasant strolling. I prefer to stay in a different area personally because I find it a bit weird being in a new development like that and the walk to Edgware Rd Tube, if you want use that one, is not very nice at night.

When we go with the kids we always stay in Southwark at either of the 2 Premier Inns there. Close to lots of restaurants and the river and good value for money.

Go to Hamleys it’s the largest and oldest toy store in the world. It’s on Regent Street.

If staying in the Paddington neighborhood simply take the Elizabeth Line from Heathrow.

Let the kids enjoy the size, noise and wonderment of trains arriving and departing Paddington station.

In Hyde Park by Kensington Palace is the Princess Diana Playground.

Lots of birds to see on the Round Pound in front of Kensington Palace. The green parrots should also be nearby. You’ll hear them before you see them.

Might also see toy boats on the Round Pond.

London Transport Museum and/or the Aquarium.

Make time to watch the pelicans being fed. https://www.royalparks.org.uk/visit/parks/st-jamess-park/pelicans-st-jamess-park

Or better yet watch the changing of the Horse Guards. https://www.royalparks.org.uk/visit/parks/st-jamess-park/horse-guards-parade

Take them to the food hall in Harrod’s

Are they un afraid of heights? Could ride in a cablecar over Thames
https://tfl.gov.uk/modes/london-cable-car/the-ifs-cloud-cable-car-experience

Hop on a double decker bus and climb upstairs. Try to sit in the front seats with the nearly floor to ceilings windows.

Take a paddle boat in Regents Park

Natural History Museum visit the dinosaur gallery.

I will say that the Heathrow Express is not usually worth it, but if you book your tickets more than 90 days in advance, it is cheaper than the Elizabeth Line.

If it's a nice day, visit the Princess Diana memorial and put your feet in the water.

If you are in Greenwich and don't mind a little walk, my can't miss Chippy in London is the Golden Chippy.

Might be a little too young, but the Natural History, Science and the Albert and Victoria (Art) museums are all great and all right next to each other, but get to the Natural History museum when it opens at it gets busy.

Put the kids to bed and see the Book of Mormon in the west end.

Battersea is nice but a little out of Central London. You can also take the boat there.

I always recommend a street food market like Borough or Camden. Camden is a nice area to check out if you have the time.

Take all this with a grain of salt as I have only been to London twice, but loved it.

Have a great trip.

I think for 10 days with such young children I’d think again about your Airbnb idea. It’s a long time to have to eat every meal out and not have any space or laundry facilities. You have lots of time so it won’t be an issue to have a little bit of travel time. There are lots of really good family areas in London. You could look at Clapham, for example, or Chiswick.

Ok thank you! Hmm yes we could try airbnb in a further out area we were thinking premier inn for the easy breakfast downstairs and it’s way cheaper than the airbnbs I was looking at in Hyde park area. Then I looked on outskirts and didn’t know if we wanted to be so far out. So chiswick? Any other good spots maybe with cute village type feel? We would love to just step out and be in a cool English village! Is surrey too far?

Wimbledon maybe?

Or if you didn’t mind a longer (30 min) train ride in you could look at some very popular commuter towns for families such as St Albans or Harpenden (to the north) or Guildford (to the south). If you stayed that far out you’d probably find it a bit tiring to go into London every day but there would be things to do locally as well.

My two daughters and I enjoyed the paddle boats in Hyde Park in 2018, I assume they still have them.

Last spring there were lots of baby ducks (and geese too I think!) in St. James' Park. They have pelicans too. And squirrels that will eat out of your hand.

The kids might enjoy the London Eye?

We took a tour to Highclere Castle, which you couldn't do with little kids. I've seen comments where people do it by car. Just make sure it's open for visitors on the day you go. Not sure kids would enjoy it, but the grounds are beautiful and they could run around a bit.

I was going to suggest Hamleys for your shopping day, but I see Robin has already mentioned it. So, here is a second vote.

I throughly enjoyed staying at the Chiswick PI but I wouldn’t recommend it for first time London visitors.

Chiswick is nice, so is Richmond but far out from the center of London. I’ve stayed in each neighborhood because I had little desire to stay in London. No need.

As you desire to see London’s sites check for availability at the PI County Hall or Tower Hill, and Aldgate.

Have I mentioned the Princess Diana Playground near Kensington Palace?

Okay thank you all so much this has been the most tip friendly group I’ve found! Aldgate I did see before as I was searching I didn’t know if ir was nice or not but I’ll check it out

St Albans and Harpenden are both good suggestions. My family lives in Harpenden so I know it well - we stayed there a lot when our kids were young. Of the two I'd go for St Albans - it's bigger, with a cathedral (St Albans Abbey), Roman ruins (Verulamium) and a market. About 30 mins from London by train, so quite doable. The only catch is the train is quite expensive, so just calculate that in when you're comparing costs.

"village feel" in London? My immediate response would be Hampstead, but that is very posh and I'm sure will be expensive.

By the way, Paddington is fine - I've stayed there a lot over the years. But you nay well find somewhere more central at a comparable price.

About the end of your visit....you wrote:

Day 8- ?? Not sure what to do in morning
check out of London hotel late , head to Heathrow hotel to stay for 2 nights
Day 9- day trip to Windsor- is this enough to take up the whole day??
Day 10- leave London head back to USA

For Day 8, I would check out of whatever hotel you're staying in, in London or elsewhere, and head to Windsor.
Stay in Windsor two nights. There's lots to do there.

Windsor Castle, a parade some days of horses and riders headed to the castle, cobblestone streets, great restaurants, lovely views of the river with swans and ducks--the kids would love this. Boat rides on the river--the kids would love this.

The small kids are going to get tired of London after a while. In Windsor, they'll have lots to do and see. There's even a good ice cream shop there. Windsor does not have the stress level or traffic of the big city. I think you will all love it.

Take a taxi to Heathrow (not far away) on the day of your flight.
The fare is about 35 pounds; not expensive.

Windsor is worth more than a day trip!
And it's WAY better to stay there for the last 2 nights rather than an airport hotel.

Usually I’d agree that it’s best to stay more central, but the op has 2 very small children. From experience, they are going to find it tiring and hard work to be touring around London every day. A quieter location will give them a chance to rest, chill out in the park and cook some of their own food. Central London is really busy so you have to be on your guard with small children all the time to make sure they’re safe. A nice family area will allow a bit of down time where they can all relax a bit more.

Maybe you could split the trip and have say 5 nights really central to tick off some of the big attractions, and then move to a self catering place somewhere a bit quieter and take the rest of the trip at a slower pace.

10 nights in a PI with a 5 and 2 year old sounds really difficult to me.

Ok thank you for the hotel tips. I’ll check those.

Good to know about Windsor! It looks so cute I didn’t know if it would take a whole day or less!

Yeah I was thinking we could stay in Greenwich since those museums and parks look really nice. Maybe we could do a few nights there just didn’t want to move our luggage too much. Maybe we should start there since there’s lots of parks and more relaxing… yeah that’s the thing staying in a small hotel room will be kinda cramped so it would be nice to go back to hotel or apartment is better to relax for a bit

If you are still looking for a "village" feel in London, perhaps Richmond is your best bet.
Richmond Park is there--a play area for the kids.
Richmond is right on the river with lots of restaurants.
It's easy to get into the center of London by using the tube from Richmond station.
Maybe check rentals there; AirBnB, etc.
Many people on this forum use Booking.com to look for rentals.

Greenwich would be really nice. The playground at Greenwich Park is very good and there’s a lot of open space. You can take the boat into Central London as well which is fun for the kids.

The Maritime Museum has an excellent indoor kids play area perfect for the ages of your children.