Rajinder Kumar (born 1934) is an Indian chemical engineer and a former professor at the Indian Institute of Science. He is known for his studies on multiphase phenomena and is an elected fellow of the Indian National Science Academy, Indian Academy of Sciences, and the Indian National Academy of Engineering. The Council of Scientific and Industrial Research, the apex agency of the Government of India for scientific research, awarded him the Shanti Swarup Bhatnagar Prize for Science and Technology, one of the highest Indian science awards for his contributions to Engineering Sciences in 1976. He received the third highest Indian civilian award of the Padma Bhushan in 2003. He is also a recipient of Om Prakash Bhasin Award and the VASVIK Industrial Research Award.