Is McCallum a irish surname or scottish surname?

Question:Irish. If it were a Scottish surname, it would be spelled MacCallum.

Best Answer - Chosen by Asker: Irish. If it were a Scottish surname, it would be spelled MacCallum.

I think you will find it is of Scottish origin remember the Scots went to Ireland and all over the world for that matter.

This is what www.ancestry.com has to say about the name,
McCallum Name Meaning and History
Scottish: Anglicized form of Gaelic Mac Coluim ‘son of Colum’, a personal name derived from Latin columba ‘dove’ (now often found as Calum). This was the name of the 6th-century missionary known in English as St. Columba (521–97), who converted the Picts to Christianity and founded an influential monastery on the island of Iona.
hope this helps.

Surname: Mccallum
This is a surname of Gaelic origins which is recorded in an astonishing number different spellings. In so far as there is a 'correct' one it is generally accepted to be MacColum, although no doubt holders of the spellings MacColum, Macallam, MacColm, MacCollom, McCallum, McCollum, McColum, McColm, Colum, and many, many, others, may disagree. The original spelling was 'Mac Coluim' or 'Mac giolla Choluim' both of which have essentially the same meaning of the 'descendant of Coluim'. The famous Irish etymologist Woulfe claimed that the name derived from 'colum' meaning 'dove', and gave examples such as Mac giolla Choluim, MacGillacolm, and MacElholm, all forms recorded before circa 1550, and now totally obsolete. In so far as the modern names forms have an epi-centre it is probably County Longford, although as MacColum it is generally regarded as an Ulster surname, and as such was recorded there in Petty's census of 1659. 'Nickname surnames' were quite common in Ireland, therefore the surname may derive from 'dove', but in a transferred sense as in 'a man of peace', a prophet . Early examples of the surname recording include Alexander McCollum who married Alice Warren at St Munchin's Church, Limerick, on May 4th 1760, and Catharine McCullum christened at Clones, County Monaghan, on May 1st 1797. England has its fair share of recordings (and its own varieties) and these include Sarah MacCollam christened at St Dunstans Church, Stepney, on June 26th 1689, James M'Colm at St Giles Church, Cripplegate, on December 16th 1750, and Agnes McColm, who married Robert Sheather at St Mary le Bone, Marylebone, London, on February 28th 1886. The first recorded spelling of the family name is shown to be that of Mac Gil Colum, which was dated 1179, recorded as the Prior of Ardstraw, County Tyrone, during the reign of King Henry 11 of England, known as 'The church builder', 1154 - 1189. Surnames became necessary when governments introduced personal taxation. In England this was known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.