肾癌（英语：Kidney cancer or renal cancer），系一种由肾脏细胞癌变引发的癌症。

两种最普遍的肾癌分别是肾细胞癌（renal cell carcinoma, 缩写为RCC）和发于肾盂的移行细胞癌（transitional cell carcinoma, 缩写为TCC）。这两种癌症的名字显示了相应癌变发生的部位。

种类不同的肾癌，其发病机理也不同，每种肾癌产生的长期效应也不相同。另外，治疗肾癌需要对癌症进行癌症分期，并根据分期结果进行相应治疗。80%的早期肾癌都是肾细胞癌，而发于肾盂的移行细胞癌又占了其余20%中的大部分 。

Kidney cancer, also known as renal cancer, is a type of cancer that starts in the cells in the kidney.

The two most common types of kidney cancer are renal cell carcinoma (RCC) and transitional cell carcinoma (TCC, also known as urothelial cell carcinoma) of the renal pelvis. These names reflect the type of cell from which the cancer developed.