Oliver Platt, a renowned individual, was born in Windsor, Ontario, to American parents, Sheila Maynard, a dedicated social worker, and Nicholas Platt, a seasoned career diplomat, both hailing from distinguished upper-class families. His maternal great-grandmother, Cynthia Roche, held a significant connection to the British royal family, being the sister of Princess Diana's maternal grandfather, Maurice Roche.
Growing up, Oliver Platt spent his formative years in various locations, including Washington, D.C., Asia, and the Middle East, which undoubtedly had a profound impact on his life and career. After completing his Bachelor of Arts degree with a major in Drama in 1983 from the prestigious Tufts University, Platt went on to hone his craft at Shakespeare & Co. under the guidance of renowned acting coach Kristin Linklater.