Spelling bee competitions are contests in which mostly younger speakers of English are pitted against each other in an attempt to find out who can spell the most complicated words for their level of English knowledge. From a linguistics standpoint, these competitions also offer a substantial amount of errors made while attempting to spell such words, which may give insight into strategies the contestants use while trying to correctly spell words. This is especially true when the contestants are not completely sure of the correct spelling. This research focuses on types and causes of errors made in English spelling bee competitions. It includes errors made by Croatian spellers in three “Pčelica Spelica” competitions held in 2018, as well as errors made by American spellers in two “Scripps Spelling Bee” competitions held in 2017 on a regional level. The errors were divided into five categories: letter substitutions, grapheme substitutions, omissions, insertions, and transpositions. Their probable causes were then induced. The results suggest American spellers to have a better foothold in dealing with spelling of unknown words. They also show knowledge of sound-to-symbol relationships in the English language. Errors made by Croatian spellers were mostly concerned with omitting certain letters, with the majority of errors occurring when letters should have been doubled. There are also certain patterns that are shared between the two groups.