I just came across this while browsing some old threads and was delighted by
Legate bringing up Nicholas Roerich above, since I had just discovered and fallen in love with Roerich's art at the time I started this thread. For a while I had several of his paintings rotating as wallpapers on my computer, and many of them have struck me as rather Tolkienish, such as this:
Bogatyrs Woke Up, or The Awakening of the Dwarves?
(Yes I know, they didn't all wake up in the same place, did they, but this just screams DWARVES! to me.)
or this:
Boris and Gleb, aka Alatar and Pallando?
(Cloaks are the wrong colour, but hey, there's enough blue in the picture.)
Others remind me of Tolkien in more subtle ways, more in their technique than their subject matter. One thing I really love about Roerich's art is his way of painting clear light and luminous colours, which IMHO is rivalled by few painters if any, and for me this resonates somewhat obliquely but very strongly with Tolkien's myth of the Two Trees and of a light that is older and holier than that which we perceive in these later ages. It can be guessed in the pictures
Legate linked, but it's most obvious in his Himalaya landscapes or a work like this:
(Terra Slavonica, 1943)