You get the train rather than the tube. Take Southwest trains and change at Clapham Junction.
You'll have to change but the best route is:
Cycle or hitch-hike
Twickenham is in the ceremonial county of Greater London. Twickenham used to be in the county of Middlesex until that county was abolished and Twickenham was absorbed into Greater London.
District Line (London Underground) from Hammersmith tube station to Victoria tube station.
By underground (tube).
The Circle Line.
There is no direct tube line between Shaftesbury Avenue and Victoria. You will have to change at Green Park.
About 10 miles
Twickenham.
No it is the Greater London Borough of Richmond.
Yes, and you can take the tube (underground) from there to everywhere else in London.
30,559
Air distance in England from Piccadilly in London center to Twickenham in the London borough of Richmond upon Thames is 9.9 miles. That is 16 kilometers. It is 8.6 nautical miles.