The Masters are a fictional race of beings in John Christopher's, The Tripods trilogy. They are first mentioned and seen in chapter 6 of The City of Gold and Lead.

Their physical appearance is excellently described, making them, easily, one of the most memorable of fictional alien races.

"They stood much taller than a man, nearly twice as tall, and broad in proportion. Their bodies were wider at the bottom than the top, four or five feet around I thought, but tapered up to something like a foot in circumference at the head. If it was the head, for there was no break in the continuity, no sign of a neck. The next thing I noticed was that their bodies were supported not on two legs, but three, these being thick but short. They had matching them three arms, or rather tentacles, issuing from a point halfway up their bodies. And their eyes - I saw that there were three of those, too, set in a flattened triangle, one above and between the other two, a foot or so below the crown. In colour the creatures were green, though I saw that the shades differed, some being dark, the green tinged with brown, and other quite pallid. That, and the fact that their heights varied to some extent, appeared to be the only means of telling one from another. I felt it was a poor one."