Seamus'
According to MLA standards, both "Seamus'" and "Seamus's" are considered correct for showing possession. The choice between the two forms may depend on personal preference or the style guide being followed.
Seamus Reed's birth name is Michael Seamus Reed.
Seamus McNulty's birth name is Seamus Patrick McNulty.
Seamus Gubbins is 6'.
Seamus Finnigan is his full name.
Seamus Finnigan is his full name.
Seamus Grew died in 1982.
Seamus McIntyre was born in 1971.
Seamus McIntyre died in 2001.
Seamus Metress was born in 1933.
Seamus Martin was born in 1942.
Seamus Casey was born in 1972.
Seamus Blake was born in 1970.