Thora is from the Old Norse Þóra — the feminine form of Thor (god of thunder, lightning, and storms) — "of Thor." Thora Birch (born 1982) — American actress; child star turned adult lead; played Jane Burnham in Sam Mendes's American Beauty (1999), which won the Academy Award for Best Picture; Enid Coleslaw in Terry Zwigoff's Ghost World (2001) — won the Golden Globe nomination and the Independent Spirit Award. Thora Borg Hallgrímsdóttir — Icelandic athlete. Thóra Kristín Þórsdóttir — Icelandic actress. Thóra Magnúsdóttir — Icelandic snowboarder.
Thora does not currently appear in the US Social Security Administration's top 1,000 girls' names, so we don't publish a US rank or birth count for it. That says nothing about the name's standing elsewhere in the world — only that it sits outside the ranked US data we rely on.
In Pythagorean numerology the letters of Thora reduce to 8, The Visionary. This is a traditional interpretive system, not a factual claim about the name.