In the US as a whole, Singh Is #396 among surnames, with about 73K individualls bearing the name. Patel is #172, 145K. Source.
I don't think the census breaks that down by state. In smaller states it would almost amount to revealing personal information.
Since we're talking about meaning, Singh means lion, from Sanskrit simha. There is speculation that Swahili simba is a derivative or cognate.
Finally I note there are non-Sikh Singhs and non-Hindu Patels.
AS far as I know, most American Sikhs live in California (especially the north), with New York City also having large numbers. So I presume that's where you'd find the most Singhs.
Accoring to SikhiWikhi
Sikhs in the United States total over 500,000 with approximately 100,000 of these living in California. Sikhs are the second largest religion in the Yuba City area. 15,000 Sikhs live in the Sacramento area and there are seven Sikh temples or gurdwaras.
Quote " All Sikhs are Singh, but not all Singhs are Sikh". Female Sikhs have the name Kaur meaning Princess. Singh and Kaur are the middle names with the proper family name following. Eg. Jagbir Singh Dahiya, or Rajbir Singh Chandi. My husband calls me Sairni which means "lion's wife".
#8 - "The "O" in Gaelic surnames means "son of" (Eg O'Brian, O'Hare) as does Mac (Or Mc) in Scotland ((Eg McDonald)."
Actually, 'ó' or the alternative form 'ua' means 'grandson', while 'mac' does indeed mean son, and is found in both Irish and Scottish names.
I have no idea why it is that 'ó' should be found only in Irish and never in Scottish Gaelic names.
Ó is grandson but in family names it may mean descendant, however remote.
The Arabic equivalent is Al, with a long a. Not thie definite article but a noun meaning "family". Al Saud is the royal family of Saudi Arabia, named for the father of Muhammad ibn Saud, who founded the family's fortunes in the 18th century. Ibn or ben is the equivalent of Irish and Scottish Mac, and is now, like them, being used as a family name that can survive for generations, like Bin Laden, not just a literal "son of".
The "Mac" in goidelic q-celtic is cognate to "map" consonant / "mab" vowel in brythonic p-celtic. The "ma" was then lost, leaving only the initial B or P. for exmaple, ab Owen (son of Owen), becomes Bowen; ab Evan, Bevan; ab Einon, Beynon; ap Harry, Parry; ap Huw, Pugh; ap Hywel, Powell; ap Rhys, Preece and Price; ap Richard, Prichard; ap Henry, Penry; ap Robert, Probert; ap Rhydderch, Prothero; ap Rosser, Prosser; ap Robin, Probyn.
I have been working a lot with a Gujarat company over the last 8 years.
In addition to the Patels and Raos (Rao is more common throughout India though) one thing that struck me was the prevalence of Shahs in the accountancy department. I was told that was because Shah used to be a name prevalent in a caste with a tradition of commerce and book-keeping and Shahs are still disproportionately represented in the ranks of accountants in Gujarat and India in general. I had assumed simple nepotism, which is also rife.
Most of the Patels in the UK came from Gujarat via Uganda and Kenya. Modi is another common name there, prominently with the bullish Chief Minister of Gujarat, Narendra Modi.
Czechs have many surnames rather different from the usual occupations, locations and fathers.
Some of them are past participles of verbs. For example my wife's maiden name is Koukal(ova) (we can ignore the feminine ova ending for these purposes); koukal means peeped. Navratil(ova) means sent back, a good name for a tennis player. A friend of ours called Dohnal(ova) means caught up. Musil (author of A Man Without Qualities) translates as Had To.
Animal names are reasonably common, but I'm not talking about the agricultural. Sysel is a reasonably common name, and translates as souslik, which is a (now rare) central European ground-squirrel. One encounters Krecek, meaning hamster, etc (there are native central European hamsters). Kafka has been germanised from kavka, meaning crow. Names of flowers and trees also occur.
Assorted adjectives turn up. Mrtvy, meaning dead, is a reasonably common name. My in-laws are called Konečny, which means final. (These ones don't take -ova in the feminine, so my sister-in-law is Konečna.)
Sorry, haven't bothered with the diacritics, apart from that one č, because konecny means something else.