diff --git a/Gemfile b/Gemfile
index ce079fdbaa..06c6fabd24 100644
--- a/Gemfile
+++ b/Gemfile
@@ -213,6 +213,8 @@ gem 'httparty'
 # Autoload dotenv in Rails. (https://github.com/bkeepers/dotenv)
 gem 'dotenv-rails'
 
+gem 'activerecord_json_validator'
+
 # ================================= #
 # ENVIRONMENT SPECIFIC DEPENDENCIES #
 # ================================= #
diff --git a/Gemfile.lock b/Gemfile.lock
index d1a8d1dba1..0fdc757d62 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -33,6 +33,9 @@ GEM
       activemodel (= 5.2.6.2)
       activesupport (= 5.2.6.2)
       arel (>= 9.0)
+    activerecord_json_validator (2.1.0)
+      activerecord (>= 4.2.0, < 8)
+      json_schemer (~> 0.2.18)
     activestorage (5.2.6.2)
       actionpack (= 5.2.6.2)
       activerecord (= 5.2.6.2)
@@ -130,6 +133,8 @@ GEM
     dragonfly-s3_data_store (1.3.0)
       dragonfly (~> 1.0)
       fog-aws
+    ecma-re-validator (0.4.0)
+      regexp_parser (~> 2.2)
     erubi (1.10.0)
     excon (0.91.0)
     execjs (2.8.1)
@@ -207,6 +212,7 @@ GEM
       guard (~> 2.1)
       guard-compat (~> 1.1)
       rspec (>= 2.99.0, < 4.0)
+    hana (1.3.7)
     hashdiff (1.0.1)
     hashie (5.0.0)
     highline (2.0.3)
@@ -223,6 +229,11 @@ GEM
       actionview (>= 5.0.0)
       activesupport (>= 5.0.0)
     json (2.6.1)
+    json_schemer (0.2.19)
+      ecma-re-validator (~> 0.3)
+      hana (~> 1.3)
+      regexp_parser (~> 2.0)
+      uri_template (~> 0.7)
     jwt (2.3.0)
     kaminari (1.2.2)
       activesupport (>= 4.1.0)
@@ -474,6 +485,7 @@ GEM
       thread_safe (~> 0.1)
     unicode-display_width (2.1.0)
     uniform_notifier (1.14.2)
+    uri_template (0.7.0)
     warden (1.2.9)
       rack (>= 2.0.9)
     web-console (3.7.0)
@@ -515,6 +527,7 @@ PLATFORMS
   x86_64-linux
 
 DEPENDENCIES
+  activerecord_json_validator
   annotate
   annotate_gem
   api-pagination
diff --git a/app/models/license.rb b/app/models/license.rb
index 858b1360c9..aa09cdd144 100644
--- a/app/models/license.rb
+++ b/app/models/license.rb
@@ -49,4 +49,20 @@ class License < ApplicationRecord
     # Remove any preferred licenses that could not be found in the table
     licenses.compact
   }
+
+  # varchar(255) NOT NULL
+  validates :name,
+    presence: { message: PRESENCE_MESSAGE },
+    length: { in: 0..255, allow_nil: false }
+
+  # varchar(255) NOT NULL
+  validates :identifier,
+    presence: { message: PRESENCE_MESSAGE },
+    length: { in: 0..255, allow_nil: false }
+
+  # varchar(255) NOT NULL
+  validates :uri,
+    presence: { message: PRESENCE_MESSAGE },
+    length: { in: 0..255, allow_nil: false }
+
 end
diff --git a/app/models/metadata_standard.rb b/app/models/metadata_standard.rb
index ea8f69c065..ef795f76cc 100644
--- a/app/models/metadata_standard.rb
+++ b/app/models/metadata_standard.rb
@@ -15,6 +15,36 @@
 #  rdamsc_id           :string
 #
 class MetadataStandard < ApplicationRecord
+
+  # =============
+  # = Constants =
+  # =============
+
+  # keep "=>" syntax as json_schemer requires string keys
+  SCHEMA_RELATED_ENTITIES = {
+    "$schema" => "http://json-schema.org/draft-04/schema#",
+    "type" => "array",
+    "items" => {
+      "type" => "object",
+      "properties" => {
+        "id" => { "type" => "string" },
+        "role" => { "type" => "string" }
+      }
+    }
+  }
+
+  SCHEMA_LOCATIONS = {
+    "$schema" => "http://json-schema.org/draft-04/schema#",
+    "type" => "array",
+    "items" => {
+      "type" => "object",
+      "properties" => {
+        "url" => { "type" => "string" },
+        "type" => { "type" => "string" }
+      }
+    }
+  }
+
   # ================
   # = Associations =
   # ================
@@ -29,4 +59,33 @@ class MetadataStandard < ApplicationRecord
     term = term.downcase
     where('LOWER(title) LIKE ?', "%#{term}%").or(where('LOWER(description) LIKE ?', "%#{term}%"))
   }
+
+  # varchar(255) DEFAULT NULL
+  validates :title,
+    length: { maximum: 255 }
+
+  # varchar(255) DEFAULT NULL
+  validates :rdamsc_id,
+    length: { maximum: 255 }
+
+  # varchar(255) DEFAULT NULL
+  validates :uri,
+    length: { maximum: 255 }
+
+  # json DEFAULT NULL
+  validates :related_entities,
+    json: {
+      schema: SCHEMA_RELATED_ENTITIES,
+      message: ->(errors) { errors }
+    },
+    allow_nil: true
+
+  # json DEFAULT NULL
+  validates :locations,
+    json: {
+      schema: SCHEMA_LOCATIONS,
+      message: ->(errors) { errors }
+    },
+    allow_nil: true
+
 end
diff --git a/app/models/repository.rb b/app/models/repository.rb
index 5db15716eb..e4e52a886a 100644
--- a/app/models/repository.rb
+++ b/app/models/repository.rb
@@ -22,6 +22,73 @@
 #
 
 class Repository < ApplicationRecord
+
+  # =============
+  # = Constants =
+  # =============
+
+  # keep "=>" syntax as json_schemer requires string keys
+  SCHEMA_INFO = {
+    "$schema" => "http://json-schema.org/draft-04/schema#",
+    "type" => "object",
+    "properties" => {
+      "types" => {
+        "type" => "array",
+        "items" => {
+          "type" => "string"
+        }
+      },
+      "keywords" => {
+        "type" => "array",
+        "items" => {
+          "type" => "string"
+        }
+      },
+      "subjects" => {
+        "type" => "array",
+        "items" => {
+          "type" => "string"
+        }
+      },
+      "access" => {
+        "type" => "string",
+        "enum" => ["open", "restricted", "closed"]
+      },
+      "provider_types" => {
+        "type" => "array",
+        "items" => {
+          "type" => "string"
+        }
+      },
+      "upload_types" => {
+        "type" => "array",
+        "items" => {
+          "type" => "object",
+          "properties" => {
+            "type" => { "type" => "string" },
+            "restriction" => { "type" => "string" }
+          },
+          "required" => ["type","restriction"]
+        }
+      },
+      "policies" => {
+        "type" => "array",
+        "items" => {
+          "type" => "object",
+          "properties" => {
+            "name" => { "type" => "string" },
+            "url" => { "type" => "string" }
+          },
+          "required" => ["name","url"]
+        }
+      },
+      "pid_system" => {
+        "type" => "string"
+      }
+    }
+  }
+
+
   # ================
   # = Associations =
   # ================
@@ -51,4 +118,39 @@ class Repository < ApplicationRecord
   scope :by_facet, lambda { |facet|
     where(safe_json_where_clause(column: 'info', hash_key: 'keywords'), "%#{facet}%")
   }
+
+  # ===============
+  # = Validations =
+  # ===============
+
+  # varchar(255) NOT NULL
+  validates :name,
+    presence: { message: PRESENCE_MESSAGE },
+    length: { in: 0..255, allow_nil: false }
+
+  # text NOT NULL
+  validates :description,
+    presence: { message: PRESENCE_MESSAGE }
+
+  # varchar(255) NOT NULL
+  validates :uri,
+    presence: { message: PRESENCE_MESSAGE },
+    length: { in: 0..255, allow_nil: false }
+
+  # varchar(255) DEFAULT NULL
+  validates :homepage,
+    length: { maximum: 255 }
+
+  # varchar(255) DEFAULT NULL
+  validates :contact,
+    length: { maximum: 255 }
+
+  # json DEFAULT NULL
+  validates :info,
+    json: {
+      schema: SCHEMA_INFO,
+      message: ->(errors) { errors }
+    },
+    allow_nil: true
+
 end