If you need to calculate places off the beaten path, here’s a lat/long finding site this site allows you to calculate the distance.
I had a few candidates, starting from southern California:
St. John’s, NL, Canada 5609 KM
Guanzhou, PRC 12510
Athens, Greece 12100
Anvers Island, Antarctica 10820
Geelong, Australia 12270
I can’t claim any record , but a few years ago it was discussed on a radio station. In particular they wanted to hear of anyone that had never been out of the Country (England). Amazingly one person rang up to say that his Grandad had not been out of his region (Cheshire) by my reckoning he cannot have travelled more than 50 miles from his birthplace.
6287.36 miles: Springfield, Illinois to Kashiwazaki, Niigata, Japan
Cape Town, South Africa to Santa Barbara, CA: 10052mi or 16177km. To do much better than that on land I’d have to visit Hawaii.
Chester, UK -2.9167
53.2000
Kaka Point, NZ 169.7833
-46.3833
Miles: 11856.60
Kilometers: 19080.82
Or somewhere close- I travelled the coastline, but there’s not much in the way of towns there.
I don’t think I can get any further on land.
A mere 4784 miles or 7700 kilometres between Kingston, Ontario, Canada and Honolulu, Hawai’i, USA.
I have in fact met people who were born in my province and have never stepped foot outside it, even to the USA, which from my house is a 50 minute drive if the traffic’s not bad. I find that amazing.
Edinburgh to Invercargill in NZ.
11692 miles (18816k), which puts me 4th or 5th, I think.
And currently I live and work within about 1/2 mile from where I was born…
From Portland, Oregon to Singapore = 8128 miles (13081km)
My wife has me beat slightly: From Tokyo, Japan to the Caribbean coast of Costa Rica = 8186 miles.
Born Washington DC. Currently living in Rhode Island. 24500.82 miles.
There’s a shorter way that’s only 359 miles though.
San Francisco CA to Buenos Aires - 6451.08
San Francisco CA to Hong Kong - 6892.90
San Francisco CA to Sydney - 7419.05
San Francisco CA to Delhi - 7668.21
San Francisco CA to Singapore - 8433.89
I really miss my job at MS - I had really got a chance to travel!!
I have a coworker that has never been outside of New England (and not even all 6 states). He could break that at any time with a 2 hour drive but somehow it just hasn’t come up yet. I had classmates in high school who had never traveled further than our field trips (about 30 miles). One had never been to Texas and the school was 1 mile from the border.
I was born in Houston, TX and still live there. The farthest place that I have been is Jakarta, Indonesia 10252.21 miles .
Actually the astronauts who traveled the farthest from the Earth never walked on the Moon. The crew of the Apollo VIII mission–Frank Borman, Jim Lovell, and William Anders–traveled 377,349 km from the Earth. As the Earth was rotating you’d have to calculate the relative distances at the time of apogee to figure out which of the three was truly farthest, but at that distance it would be a rounding error. None of those three ever made it to the surface of the Moon; Lovell, of course, commanded the ill-fated Apollo XIII mission that was planned to land at a site in the Fra Mauro highlands but that landing was aborted due to a fire on-board the Service Module.
Stranger
I have a friend that was born in Hawaii, who returned from some missionary work in Africa. I have to check with her, since if she was in Botswana she might win.
Beirut, Lebanon to Christchurch, NZ (only stopped in the airport): 10052 miles, which is about the maximum I can achieve, since the antipode of Beirut is somewhere in the southern Indian ocean. Furthest I’ve left the airport would be Fiji, which is about 9,900 miles.
Newark, US -74.1728
40.7356
Hobart, AS 147.3333
-42.9167
Miles: 10309.03
I’d have better numbers if I could measure from where I live now instead of where I was born.
Sacramento, CA to Rome, Italy: 6176 Miles
I’d be aiming for a spot in the Indian Ocean. It looks like the nearest land is the Kerguelen Islands (11,552 Miles). They’re a bit remote, but the restaurant there gets great reviews! 
The closest land to Portland, Oregon’s antipode seems to be some island int eh French Southern and Antarctic Lands that Google Maps doesn’t bother to name.
I imagine it is difficult to get there by plane.
It looks to me like the best combination is Spain and New Zealand and the Second is Hawaii and Botswana. The third would be Perth and Bermuda.