Block number may refer to:
Aviation United States Department of Defense aerospace vehicle designation, for general US military usage 1962 United States Tri-Service aircraft designation system, for the 1960s/Cold War era US military term
Built environment City block and House numbering, for general urban planning usage Census block and Census block group, for the US Census terminology Lot and block survey system, for the North American survey term Community development block, for the Indian development term Borough, Block and Lot, for New York City planning usage
Computing Logical block addressing, for the data storage term Block cipher, for cryptographic usage Spreadsheet cells, for spreadsheet usage
Other Call blocking, for general telephone usage Telephone number pooling, for the US Telephone Numbering Plan term Numberblocks, for the BBC television series