The schools around King's Cross are excellent on paper, and the paper is unusually consistent. Every graded school in the borough is good or better. About half are outstanding. None has been marked down. The catch for a family here is finding a flat big enough to need one.
Camden's graded schools make a clean sheet: Ofsted rates 25 of the 25 settings with a published grade across the borough as good or better, every one of them. Thirteen of those are outstanding and 12 good, and none sits at requires improvement or inadequate. Another 26 Camden settings hold no published grade yet, either because they are new or because they haven't been inspected under the current framework, so they are simply missing from the count. A parent who wants a school to worry about will have to look in a different borough.
Getting into one is a separate question. Camden Council allocates places under its published admissions rules, and living a short walk from a school's gates doesn't secure a place there, whatever the buyer two floors up told you at the lift. The Department for Transport's 2019 modelling puts the nearest primary about four minutes' walk from the average home here and the nearest secondary about 16 minutes on foot, or roughly 16 minutes by public transport. Distance is the cheap part. With most homes being one- and two-bedroom flats and couples with children making up only about 10% of households, the family that finds a three-bed near a good primary has already done the hard bit. Look up how far from the gate last year's final offers reached at the schools you want, because in streets this dense that distance can be shorter than the walk to the station.
The one place of learning inside the area itself is Capital City College, a further-education college, which takes over after the school years. The primaries and secondaries families actually choose between are spread across the rest of Camden, and the inspection record says the choice is between good and better.
Schools are one of King's Cross's real strengths, and the hard part for families here is the housing that goes with them.