diff --git a/dbt_common/contracts/config/base.py b/dbt_common/contracts/config/base.py
index a16b4d9b..42acb1bf 100644
--- a/dbt_common/contracts/config/base.py
+++ b/dbt_common/contracts/config/base.py
@@ -17,11 +17,11 @@
 @dataclass
 class BaseConfig(AdditionalPropertiesAllowed, Replaceable):
     # enable syntax like: config['key']
-    def __getitem__(self, key):
+    def __getitem__(self, key: str) -> Any:
         return self.get(key)
 
     # like doing 'get' on a dictionary
-    def get(self, key, default=None):
+    def get(self, key: str, default: Any = None) -> Any:
         if hasattr(self, key):
             return getattr(self, key)
         elif key in self._extra:
@@ -30,13 +30,13 @@ def get(self, key, default=None):
             return default
 
     # enable syntax like: config['key'] = value
-    def __setitem__(self, key, value):
+    def __setitem__(self, key: str, value) -> None:
         if hasattr(self, key):
             setattr(self, key, value)
         else:
             self._extra[key] = value
 
-    def __delitem__(self, key):
+    def __delitem__(self, key: str) -> None:
         if hasattr(self, key):
             msg = (
                 'Error, tried to delete config key "{}": Cannot delete ' "built-in keys"
@@ -60,7 +60,7 @@ def _content_iterator(self, include_condition: Callable[[Field], bool]):
     def __iter__(self):
         yield from self._content_iterator(include_condition=lambda f: True)
 
-    def __len__(self):
+    def __len__(self) -> int:
         return len(self._get_fields()) + len(self._extra)
 
     @staticmethod
@@ -221,7 +221,7 @@ def _merge_field_value(
     merge_behavior: MergeBehavior,
     self_value: Any,
     other_value: Any,
-):
+) -> Any:
     if merge_behavior == MergeBehavior.Clobber:
         return other_value
     elif merge_behavior == MergeBehavior.Append:
diff --git a/dbt_common/invocation.py b/dbt_common/invocation.py
index 0e5d3206..adbd7d18 100644
--- a/dbt_common/invocation.py
+++ b/dbt_common/invocation.py
@@ -7,6 +7,6 @@ def get_invocation_id() -> str:
     return _INVOCATION_ID
 
 
-def reset_invocation_id():
+def reset_invocation_id() -> None:
     global _INVOCATION_ID
     _INVOCATION_ID = str(uuid.uuid4())
diff --git a/dbt_common/semver.py b/dbt_common/semver.py
index fbdcefa5..4c411911 100644
--- a/dbt_common/semver.py
+++ b/dbt_common/semver.py
@@ -67,7 +67,7 @@ class VersionSpecification(dbtClassMixin):
 _VERSION_REGEX = re.compile(_VERSION_REGEX_PAT_STR, re.VERBOSE)
 
 
-def _cmp(a, b):
+def _cmp(a, b) -> int:
     """Return negative if a<b, zero if a==b, positive if a>b."""
     return (a > b) - (a < b)
 
@@ -123,7 +123,7 @@ def to_range(self) -> "VersionRange":
 
         return VersionRange(start=range_start, end=range_end)
 
-    def compare(self, other):
+    def compare(self, other: "VersionSpecifier") -> int:
         if self.is_unbounded or other.is_unbounded:
             return 0
 
@@ -192,16 +192,16 @@ def compare(self, other):
 
         return 0
 
-    def __lt__(self, other) -> bool:
+    def __lt__(self, other: "VersionSpecifier") -> bool:
         return self.compare(other) == -1
 
-    def __gt__(self, other) -> bool:
+    def __gt__(self, other: "VersionSpecifier") -> bool:
         return self.compare(other) == 1
 
-    def __eq___(self, other) -> bool:
+    def __eq___(self, other: "VersionSpecifier") -> bool:
         return self.compare(other) == 0
 
-    def __cmp___(self, other):
+    def __cmp___(self, other: "VersionSpecifier") -> int:
         return self.compare(other)
 
     @property
@@ -221,7 +221,7 @@ def is_exact(self) -> bool:
         return self.matcher == Matchers.EXACT
 
     @classmethod
-    def _nat_cmp(cls, a, b):
+    def _nat_cmp(cls, a, b) -> int:
         def cmp_prerelease_tag(a, b):
             if isinstance(a, int) and isinstance(b, int):
                 return _cmp(a, b)
@@ -358,23 +358,23 @@ def __init__(self, *args, **kwargs) -> None:
             matcher=Matchers.EXACT, major=None, minor=None, patch=None, prerelease=None, build=None
         )
 
-    def __str__(self):
+    def __str__(self) -> str:
         return "*"
 
     @property
-    def is_unbounded(self):
+    def is_unbounded(self) -> bool:
         return True
 
     @property
-    def is_lower_bound(self):
+    def is_lower_bound(self) -> bool:
         return False
 
     @property
-    def is_upper_bound(self):
+    def is_upper_bound(self) -> bool:
         return False
 
     @property
-    def is_exact(self):
+    def is_exact(self) -> bool:
         return False
 
 
diff --git a/dbt_common/utils/casting.py b/dbt_common/utils/casting.py
index f366db7f..076d4c12 100644
--- a/dbt_common/utils/casting.py
+++ b/dbt_common/utils/casting.py
@@ -1,7 +1,7 @@
 # This is useful for proto generated classes in particular, since
 # the default for protobuf for strings is the empty string, so
 # Optional[str] types don't work for generated Python classes.
-from typing import Any, Dict, Optional
+from typing import Any, Dict, Mapping, Optional
 
 
 def cast_to_str(string: Optional[str]) -> str:
@@ -18,8 +18,9 @@ def cast_to_int(integer: Optional[int]) -> int:
         return integer
 
 
-def cast_dict_to_dict_of_strings(dct: Dict[Any, Any]) -> Dict[str, str]:
+def cast_dict_to_dict_of_strings(dct: Mapping[Any, Any]) -> Dict[str, str]:
     new_dct: Dict[str, str] = {}
+
     for k, v in dct.items():
         new_dct[str(k)] = str(v)
     return new_dct
diff --git a/dbt_common/utils/connection.py b/dbt_common/utils/connection.py
index 5c76fe7f..cc4e1ce4 100644
--- a/dbt_common/utils/connection.py
+++ b/dbt_common/utils/connection.py
@@ -1,4 +1,5 @@
 import time
+from typing import Callable
 
 from dbt_common.events.types import RecordRetryException, RetryExternalCall
 from dbt_common.exceptions import ConnectionError
@@ -7,7 +8,7 @@
 import requests
 
 
-def connection_exception_retry(fn, max_attempts: int, attempt: int = 0):
+def connection_exception_retry(fn: Callable, max_attempts: int, attempt: int = 0):
     """Handle connection retries gracefully.
 
     Attempts to run a function that makes an external call, if the call fails
diff --git a/dbt_common/utils/jinja.py b/dbt_common/utils/jinja.py
index 260ccb6a..c9d9fa8e 100644
--- a/dbt_common/utils/jinja.py
+++ b/dbt_common/utils/jinja.py
@@ -1,3 +1,5 @@
+from typing import Optional
+
 from dbt_common.exceptions import DbtInternalError
 
 
@@ -5,20 +7,20 @@
 DOCS_PREFIX = "dbt_docs__"
 
 
-def get_dbt_macro_name(name) -> str:
+def get_dbt_macro_name(name: str) -> str:
     if name is None:
         raise DbtInternalError("Got None for a macro name!")
     return f"{MACRO_PREFIX}{name}"
 
 
-def get_dbt_docs_name(name) -> str:
+def get_dbt_docs_name(name: str) -> str:
     if name is None:
         raise DbtInternalError("Got None for a doc name!")
     return f"{DOCS_PREFIX}{name}"
 
 
 def get_materialization_macro_name(
-    materialization_name, adapter_type=None, with_prefix=True
+    materialization_name: str, adapter_type: Optional[str] = None, with_prefix: bool = True
 ) -> str:
     if adapter_type is None:
         adapter_type = "default"
@@ -26,10 +28,10 @@ def get_materialization_macro_name(
     return get_dbt_macro_name(name) if with_prefix else name
 
 
-def get_docs_macro_name(docs_name, with_prefix=True):
+def get_docs_macro_name(docs_name: str, with_prefix: bool = True) -> str:
     return get_dbt_docs_name(docs_name) if with_prefix else docs_name
 
 
-def get_test_macro_name(test_name, with_prefix=True):
+def get_test_macro_name(test_name: str, with_prefix: bool = True) -> str:
     name = f"test_{test_name}"
     return get_dbt_macro_name(name) if with_prefix else name