# Mountcastle (surname)

Source: https://namelineage.com/surname/mountcastle/  
Publisher: Name Lineage. Counts from the US Census Bureau; origin and etymology from Wiktionary; bearers from Wikidata. Data updated 2026-11-11.

A surname from Irish.

| Field | Value |
|---|---|
| Origin | Irish |
| Type | place, taken from where an ancestor lived or came from |
| People in the US (2010 Census) | 620 |
| US rank (2010) | 36,154 of 162,253 |
| How often | about 1 in every 497,977 people |
| Change since 2000 | +7.1% (579 in 2000) |
| Pronunciation | not recorded |
| Variant spellings | none recorded |

## Etymology

Perhaps a habitational surname from a now lost place, from mount + castle. Alternatively, a further Anglicization of the Irish surname Mountcashell.

## Who carries it

Share of people named Mountcastle in the 2010 US Census by the Census's own race and ethnicity groups. The Census suppresses a share when the count behind it is small.

| Group | Share |
|---|---|
| White (not Hispanic) | 87% |
| Black (not Hispanic) | 7.7% |
| Hispanic or Latino (any race) | 2.3% |
| Two or more races | 1.6% |

## Similar surnames

Mounts, Monts, Mendoza, Mendez, Montgomery, Montes, Montague, Mendes, Montez, Mandujano, Mintz, Montesdeoca.

## How to read these numbers

A Census count is people alive and counted in 2010, not births, and names occurring fewer than 100 times are not published at all. Ethnicity shares are the Census's own categories.