Manny Halican - Pahu Kani. Based in Waianae, Hawaii. He in a member of the Ukulele Guild of Hawaii.
Kevin Hall - Timberline. Based in Wilno, Ontario, Canada. Started in 1969 and had a 70's firm called Ruby Banjos. Started Timberline in 1978. Timberline Guitars in California. was a separate company but to avoid legal stuff Kevin became a consultant for them.
Bill Hardin - Bear Creek Guitars. Based in Kula, Maui, Hawaii. Started in 1979 and has worked as a luthier for O.M.I. Dobro and Santa Cruz Guitars before starting on his own in 1995
Patrick Hawley - Based in Ottawa, Ontario, Canada. Largly self taught, he started in the mid 2000's and went full time in 2012
Ryukichi Hayakawa - Stream. Based in Kunitachi-chi, Tokyo, Japan. I have seen banjoleles made by him as well as ukuleles
David Hurd - Kawika. Based in Hilo, the Big Island, Hawaii. He is self-taught and began making Ukuleles as a hobby in 1985. Also an author, of books about Ukuleles and Ukulele building. He retired from Ukulele manufacture some time before 2011.
Graham Hurlock - Barebones. Based in Waterview, Auckland, New Zealand. Started Barebones in 2012 having worked previously as a instrument repairer. Started making ukuleles in 2013 and rebuilds old banjoleles.