Yes, there is a Saint Elmo, sometimes known as Saint Erasmus.

Erasmus is the patron saint of Gaeta, Italy.

Saint Erasmus of Formiae , also known as Saint Elmo, was a Christian saint and martyr who died ca. 303. This was before a formal canonization process was in place so he would have been declared a saint by the early Christian community with the approval of the local bishops.

Erasmus is the patron saint of:
against abdominal pains
against appendicitis
against birth pains
against childhood intestinal disease
against colic
against danger at sea
against intestinal disorders
against seasickness
against stomach diseases
against storms
ammunition workers
boatmen
childbirth
explosives workers
Gaeta, Italy
mariners
navigators
ordnance workers
sailors
watermen
women in labour

St. Elmo is another name for St. Erasmus of Formiae