oh, wonderful, it's not just me! may I present to you: sherlock holmes and how he was totally jewish. evidence, in the order of 'ehh I thought of it in this order':
his nose is repeatedly described as aquiline. like honestly given doyle's famous consistency that's probably one of his more consistent character traits.
sherlock was. like. not a name anyone gave their kid before. seriously in like twenty years around when he was born there were like under 20 kids named sherlock. you know what it's really close to? like, suspiciously close to? shylock, one of the most famous anglo-jewish literary characters. it could easily have been a name to 'pass' because his real name was, like, shlomo.
also the whole thing where mycroft just. like. appears out of nowhere? yeah, that's mighty suspicious. UNLESS of course mycroft started hiding his jewish identity recently
seriously as noted his family background is. like. suspiciously vague. notably, he says his grandmother was the sister of 'the french artist vernet'. there was more than one french artist named vernet, which makes it kinda weird he didn't clarify. of course, if he was making it up that vagueness would work in his favor.
when we do see the last name of a canonical relative, it's verner. which just doesn't sound very french.
from the opening of the greek interpreter: "During my long and intimate acquaintance with Mr. Sherlock Holmes I had never heard him refer to his relations, and hardly ever to his own early life...His aversion to women and his disinclination to form new friendships were both typical of his unemotional character, but not more so than his complete suppression of every reference to his own people." now, his own people fairly clearly means "his family". but that's a very awkward phrasing and definitely brings to mind 'jews' more than 'oh yeah his brother'
there's almost no theological references. when watson makes a list of holmes' abilities and his knowledge, theology just doesn't appear. this suggests three possibilities: a) it naturally didn't come up enough for watson to have data on it, which seems unlikely (I doubt swordsmanship came up often, but there's a note on his abilities), b) holmes deliberately avoided the subject, or c) to write it down would involve revealing holmes' faith, which watson knew of when publishing, and so watson did not mention it.
there's a conspicuous lack of references to churches and stuff. I can think of two: victor trevor's dog biting him as he was going to the chapel (probably required at the time in university) and when we see him in a church in a scandal in bohemia, witnessing the marriage of irene adler to godfrey norton, he explicitly describes that as "the most preposterous position in which I ever found myself in my life". which is a little odd, because IMO holding the ancient English crown after you found it buried in an acquaintance's yard while trying to track down the vanished butler who tried to find it via clues in a family coming-of-age ritual handed down over the centuries, is somewhat more preposterous (that's in the musgrave ritual, which takes place before holmes and watson meet). unless there's some other factor. if he's jewish that goes a long way towards explaining that.
the stradivarius he got from "a Jew broker's in Tottenham Court Road for fifty-five shillings", another sign of contact with the Jewish community (we only know that the man looked, to Watson's eyes, like a 'Jew pedlar')
okay to be fair there is evidence against. in shoscombe old place, he makes a passing remark to someone being 'in the hands of the Jews' after someone else used the phrase, which is fairly explainable by a a) him covering his Judaism, b) Watson's paraphrasing, or c) wanting to be precise about words. In Hound of the Baskervilles there's a mention of 'the Father of Evil'. in the blue carbuncle, set two days after Christmas, he refers to it as being 'the season of forgiveness'. but honestly, that's about it.