Thomas Rainbird (also spelt as Reynberd; 1485 – July 24, 1539) was an English yeoman and the 14th great-grandfather of Cometan, classified as one of Cometan’s distant paternal ancestors in the Stringfellow family line. Born in Walsham-le-Willows, Suffolk, Thomas is recorded as having been the husband of Lady Isabel Millyzant (1490 – ????). He is also known to have been the son of Lawrence Ryxe Rainbird (1460 – 1505) and Margaret May (1455 – 1505). Thomas is recorded as having died at the fifty-four in Walsham-le-Willows with his will having been dated 20th July 1539 just four days before his death.
In Cometanic ancestry, Thomas is categorised as part of the 16th generation retrograde, classifying him as a distant ancestor of Cometan.