Aside from Ben Harper, which artists are similar to Jack Johnson?

Answer 1

check out Shawn Mullins ,similar style
also checkout bob Marley he and jack johnson did a few pieces together
heres a few Shawn Mullins tunes to check out
anchored in you
the gulf of Mexico
twin rocks Oregon
soul core
tanning bed song
ballad of billy Jo McKay

I think you will find these to your liking