2000
#135,837
National surname rank
Recorded bearers 114
First available Census row
Per 100,000 0.04
Very Rare Last name
Mortorff
A locational surname that likely referred to a place with the name "Mortorff."
According to the 2020 US Census Bureau surname tables, roughly 125 Americans carry the last name Mortorff. That puts it at #150,205 in the national surname ranking, appearing at a frequency of 0.04 per 100,000 people (about 1 in 2,742,035 residents).
This page is the full Name Census profile for the Mortorff surname. You will find the Census Bureau frequency data, a multi-census history view, an ancestry and ethnicity breakdown based on self-reported demographics, the name's meaning and origin where available, and answers to the most common questions people ask about this surname.
Bearers in the US
125
1 in 2,742,035
Census rank
#150,205
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
109
very rare in the US
Popularity narrative
The Census Bureau recorded 109 bearers of the surname Mortorff in its 2020 decennial surname file. At a rate of 0.04 per 100,000 residents, it holds the 150205th position in the national surname ranking.
Among Census respondents with the surname Mortorff, the largest self-reported group is White at 94.5%. The next largest groups are Asian/Pacific Islander (2.8%) and Two or More Races (2.8%).
Origin
Meaning and origin of Mortorff
The surname Mortorff has its roots in Germany, where it first appeared in the 16th century. It is believed to have originated from the Old German word "mort," meaning "marsh" or "swamp," and "orf," meaning "village" or "settlement." This suggests that the name may have been derived from a place name referring to a village or settlement near a marshy area.
One of the earliest recorded mentions of the name Mortorff can be found in the records of the village of Mörsdorf, located in the modern-day German state of Rhineland-Palatinate. The name was spelled "Morsdorf" in these early documents, which date back to the late 1500s.
In the 17th century, the name began appearing in various church records and tax registers across parts of Germany, with variations in spelling such as "Mortorf," "Mordorff," and "Mortorff." This suggests that the name had spread beyond its original region and had become more widespread.
One notable individual with the surname Mortorff was Johann Mortorff, a German philosopher and theologian who lived in the late 16th century. He was known for his writings on religious topics and his work at the University of Heidelberg.
Another significant figure bearing the name was Gerhard Mortorff, a German architect who lived in the 18th century. He was responsible for designing several notable buildings in cities such as Berlin and Dresden, including the Baroque-style Mortorff Palace in Dresden.
In the 19th century, the surname Mortorff began appearing in records of German immigrants to the United States. One such individual was Heinrich Mortorff, who arrived in New York in 1852 and later settled in the Midwest, where he worked as a farmer.
Other notable individuals with the surname Mortorff include Friederike Mortorff, a German artist known for her landscape paintings in the late 19th century, and Wilhelm Mortorff, a German soldier who served in World War I and later became a respected military historian.
While the surname Mortorff is not among the most common in Germany or other parts of the world, it has a rich history dating back several centuries and is closely tied to the regions of Germany where it first emerged.
Demographics
Ancestry and ethnicity for Mortorff
Among Census respondents with the surname Mortorff, the largest self-reported group is White at 94.5%. The next largest groups are Asian/Pacific Islander (2.8%) and Two or More Races (2.8%).
The bar chart below shows how Mortorff bearers described their own race and ethnicity on the 2020 Census form. The Census Bureau groups responses into six broad categories: White, Black or African American, Hispanic or Latino, Asian and Pacific Islander, American Indian and Alaska Native, and Two or More Races. When a category has too few respondents for a given surname, the Bureau suppresses the figure to protect individual privacy, which is why some names show fewer than six slices.
Percentages are shown for every Census year so the breakdown stays comparable over time. When the source file also includes raw headcounts, Name Census shows those alongside the percentages in the legend.
Keep in mind that these are self-reported numbers. A person's surname does not determine their race or ethnicity, and the distribution you see here reflects the specific population who happened to carry the Mortorff surname at the time of the 2020 Census, not any inherent property of the name itself.
- White94.5% · 103
- Asian and Pacific Islander2.8% · 3
- Two or more races2.8% · 3
Timeline
Historical Census data for Mortorff
Mortorff appears in 3 published Census surname files: 2000, 2010, 2020. The cards below show how the name's rank and bearer count changed across each release.
2010
#136,449
National surname rank
Recorded bearers 123
+9 bearers (+7.9%)
Per 100,000 0.04
Rank movement Down 612 places
2020
#150,205
National surname rank
Recorded bearers 109
-14 bearers (-11.4%)
Per 100,000 0.04
Rank movement Down 13,756 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #135,837 | 114 | 0.04 | First available Census row | First available Census row |
| 2010 | #136,449 | 123 | 0.04 | +9 bearers (+7.9%) | Down 612 places |
| 2020 | #150,205 | 109 | 0.04 | -14 bearers (-11.4%) | Down 13,756 places |
For 2020, the Census Bureau published race and Hispanic-origin columns as counts rather than percentages. Name Census converts those counts back into shares so the ancestry section stays comparable with the older surname files.
Year on year
2010 vs 2020 Census
How has the Mortorff surname changed between Census years? The chart shows bearer count side by side, and the table compares rank, count, and frequency.
Census year comparison
20102020
| Metric | 2010 | 2020 | Change |
|---|---|---|---|
| Rank | #136,449 | #150,205 | -10.1% |
| Count | 123 | 109 | -11.4% |
| Per 100K | 0.04 | 0.04 | -8.8% |
Between the 2010 and 2020 Census, the number of Mortorff bearers went from 123 to 109 (-11.4% change). The surname moved down 13,756 positions in the national ranking, going from #136,449 to #150,205.
FAQ
Mortorff surname: questions and answers
How many people in the U.S. have the surname Mortorff?
Name Census estimates that about 125 living Americans carry the surname Mortorff. Using the current population baseline, that works out to roughly 1 in 2,742,035 residents.
How common is Mortorff?
Mortorff ranks #150,205 in the 2020 Census surname tables and is classified on this site as "Very Rare." The Census recorded the name at a frequency of 0.04 per 100,000 residents, which is about 0 people out of every 100,000.
How many people with this surname were counted in the Census?
The raw 2020 Census file counted 109 people with the surname Mortorff. That is different from the site's living-bearer estimate (125), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.04 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.04 per 100,000 means that if you picked a random group of 100,000 U.S. residents, you would expect about 0 of them to have the surname Mortorff.
Has Mortorff become more or less common over time?
Between 2010 and 2020, the surname Mortorff went from 123 recorded bearers to 109. That is a decrease of 14 (-11.4%). In the national ranking it fell from #136,449 to #150,205.
What does the Census say about the background of Mortorff?
Among Census respondents with the surname Mortorff, the largest self-reported group is White at 94.5%. The next largest groups are Asian/Pacific Islander (2.8%) and Two or More Races (2.8%). These figures come from the 2020 Census Bureau surname tables, based on how respondents described their own race and ethnicity.
Which group reports this surname most often?
White is the largest self-reported group for the surname Mortorff in the 2020 Census, accounting for 94.5% (103 people in the source table).
What is the full ancestry breakdown?
Mortorff appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (94.5%), Asian/Pacific Islander (2.8%), Two or More Races (2.8%). For 2020, the source file also published raw headcounts for each group, which is why this page can show both percentages and counts in the ancestry section.
Is this page using the latest Census data?
Yes. This page is using the latest surname file currently loaded on Name Census, which is 2020. The historical section above also keeps any older Census surname entries we have for Mortorff (2000, 2010, 2020).
Does the Census include every surname?
No. The Census Bureau only publishes surnames that appeared at least 100 times in a given decennial Census. That means very rare surnames are excluded entirely, and a surname can appear in one Census release but disappear from a later one if it falls below the reporting threshold.
Why don't the ancestry percentages always add up to exactly 100%?
There are two main reasons: rounding and suppression. The Census Bureau rounds published values, and it may suppress very small cells to protect privacy. For 2020, the Bureau also published raw group counts rather than direct percentages, so Name Census converts those counts back into shares for comparability across census years.
What does Mortorff mean?
A locational surname that likely referred to a place with the name "Mortorff." The fuller origin note on this page goes into more detail.
Where does the surname data come from?
All surname statistics on Name Census are drawn from the US Census Bureau's decennial surname frequency tables. These files list every surname that appeared 100 or more times in the 2020 Census, along with a count, a per-100,000 rate, and a self-reported demographic breakdown. You can read the full explanation on our methodology page.
How does Name Census estimate living bearers?
For surnames, Name Census does not age cohorts the way it does for first names. Instead, it takes the Census Bureau's published frequency for Mortorff (0.04 per 100,000) and applies that rate to the current U.S. resident population to estimate how many living Americans have the surname today.
How many people have the last name Mortorff?
Find out how many people are called Mortorff on our sister site HowManyOfMe.org — a quick modern estimate with the living-bearer count front and centre.