I've seen Ismay (iz-may) getting a lot of love online lately, so I thought I'd give you the history. There might be no coincidence that Ismay sounds so close to Esme, meaning "esteemed," although a lot of people like to debate where it came from and how it was used. Some say it's a variant of Ismene, meaning "knowledgeable," or Ismenia, whose origins are equally debatable, but could come from Yasmin. Some say it's a Germanic compound name from iron and strength, some say it has Celtic origins, and some say it is a variant (possibly Anglicized) spelling of Esme, which is French. This is evidenced by variant spellings like Esmay. However, the first record of Ismay could be one in Lancashire, England, and the name could predate the Norman conquest in some form. I've also seen it argued that Ismay comes from Ishmael.
Ismay can be found as a surname, as is the case with famous British businessman Bruce Ismay, associated with the Titanic, but also as a first name, as in Ismay Thorne, a British children's author, and Ismay Johnston, a New Zealand actress. It was a matronymic surname (the mother's given name passed to the son as his surname) since at least the 16th century, possibly the 13th century (according to K. M. Shear in Llewellyn's Complete Book of Names), and in use in medieval times in England. Variants recorded include Ysmay, Isemay, Isamaya and Ysemay, and it is important to note that different spellings were very common until the English language was standardized. There are records of the name being used in North Wales, and Ismay would mean "lower field" in Welsh. Ismey has also been used in Iceland. The Oxford Dictionary of English Christian Names confirms Ismay and variants were in use in 13th century England. Like Winston, surnames became necessary when the government introduced personal taxation, or the Poll Tax. It can also be found in a couple of books from around the 1980's, such as "What's Bred in the Bone" by Robertson Davies, whose character lived in the 1930's.
White Pages tells us there are 172 people in the U.S. with the first name Ismay, and the most popular decade for the name was 1924. There are also 110 people with Ismay as a last name. In 2011 Ismay was not used, although several similar sounding names were - Ismene, Isatou, Isaura, Islay and of course, Isabella and Esme.
So here's what we know for sure:
Ismay was in use between 1450 and 1650
It has survived until now in both given name and surname form, but is rarely used
It has been used in literature
So, is Ismay an Anglicized variant of Esme, Ismene, Ismenia, Ismeria, or an original Celtic name? I'm going to guess that a) since it was in use in England, Iceland, and possibly Wales, and b) since I haven't seen records of it in France, and c) since the Poll Tax was in England, that it is not from Ismene (Greek) or Ismagi (Germanic), although names do travel. That leaves two options: from Ismenia, which may or may not be Celtic, or a completely unrelated Celtic name. For information on a similar name, Ismeria, please visit the post on British Baby Names.