diff --git a/src/bioregistry/data/bioregistry.json b/src/bioregistry/data/bioregistry.json
index ffefc1d80..baf2966ac 100644
--- a/src/bioregistry/data/bioregistry.json
+++ b/src/bioregistry/data/bioregistry.json
@@ -16407,6 +16407,36 @@
     "pattern": "^\\d{7}$",
     "uri_format": "http://purl.obolibrary.org/obo/CHMO_$1"
   },
+  "chr": {
+    "contact": {
+      "email": "cjmungall@lbl.gov",
+      "github": "cmungall",
+      "name": "Chris Mungall",
+      "orcid": "0000-0002-6601-2165"
+    },
+    "contributor": {
+      "email": "jhc@lbl.gov",
+      "github": "caufieldjh",
+      "name": "Harry Caufield",
+      "orcid": "0000-0001-5705-7831"
+    },
+    "description": "The Chromosome Ontology is an automatically derived ontology of chromosomes and chromosome parts.",
+    "download_json": "https://raw.githubusercontent.com/monarch-initiative/monochrom/refs/heads/master/chr.json",
+    "download_obo": "https://raw.githubusercontent.com/monarch-initiative/monochrom/refs/heads/master/chr.obo",
+    "download_owl": "https://raw.githubusercontent.com/monarch-initiative/monochrom/refs/heads/master/chr.owl",
+    "example": "10090-chr10qC",
+    "github_request_issue": 1265,
+    "homepage": "https://github.com/monarch-initiative/monochrom",
+    "license": "BSD-3",
+    "name": "Chromosome Ontology",
+    "repository": "https://github.com/monarch-initiative/monochrom",
+    "reviewer": {
+      "email": "cthoyt@gmail.com",
+      "github": "cthoyt",
+      "name": "Charles Tapley Hoyt",
+      "orcid": "0000-0003-4423-4370"
+    }
+  },
   "cido": {
     "aberowl": {
       "description": "The Coronavirus Infectious Disease Ontology (CIDO) aims to ontologically represent and standardize various aspects of coronavirus infectious diseases, including their etiology, transmission, epidemiology, pathogenesis, diagnosis, prevention, and treatment.",