Round Rock, Texas ZIP Codes

ZIP records
3
Sum of listed ZIP population estimates
184,922
Counties represented
1
Population range
56,691–66,171 per ZIP

Population sum includes positive estimates in these ZIP records; it is not an official city population.

Top ZIP Codes by Population

Rank	ZIP Code	City	County	Population estimate
1	78665	Round Rock	Williamson	66,171
2	78664	Round Rock	Williamson	62,060
3	78681	Round Rock	Williamson	56,691

Counties represented

Williamson County

All ZIP Codes in Round Rock

ZIP 78664 — Williamson County
ZIP 78665 — Williamson County
ZIP 78681 — Williamson County

Browse all ZIP data for Texas

Methodology: ZIP records are grouped by the source file's primary city and state fields. Population ranges and sums use positive ZIP-level estimates; sums should not be read as official city totals. County links use each record's listed county assignment.