Elspeth is the Scottish form of Elizabeth — from the Hebrew Elisheba ("my God is my oath"). Used in Scottish naming since the 14th century. Her 2017 memoir Lone Rider: The First British Woman to Motorcycle Around the World was a Sunday Times bestseller and has been translated into 8 languages. Elspeth Huxley (1907-1997) — English colonial Kenyan-British writer; The Flame Trees of Thika (1959) was adapted into a 1981 BBC series. Elspeth Probyn — Australian feminist theorist. Saint Elspeth is the Scottish equivalent of Saint Elizabeth.
Elspeth 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 Elspeth reduce to 4, The Builder. This is a traditional interpretive system, not a factual claim about the name.