diff --git a/CHANGELOG.md b/CHANGELOG.md
index d34d06330..5eab3b8c3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 ## 2.0.0 under development
 
+- Enh #816: Allow scalar values for `$columns` parameter of `Query::select()` and `Query::addSelect()` methods (@Tigrov)
 - Enh #806: Non-unique placeholder names inside `Expression::$params` will be replaced with unique names (@Tigrov)
 - Enh #806: Build `Expression` instances inside `Expression::$params` when build a query using `QueryBuilder` (@Tigrov)
 - Enh #766: Allow `ColumnInterface` as column type. (@Tigrov)
diff --git a/UPGRADE.md b/UPGRADE.md
index dde268f37..6b040126c 100644
--- a/UPGRADE.md
+++ b/UPGRADE.md
@@ -19,6 +19,14 @@ in `addColumn()` method of your classes that implement the following interfaces:
 - `Yiisoft\Db\QueryBuilder\AbstractDDLQueryBuilder`;
 - `Yiisoft\Db\QueryBuilder\AbstractQueryBuilder`.
 
+### Scalar values for columns in `Query`
+
+Change `$columns` parameter type from `array|string|ExpressionInterface` to `array|bool|float|int|string|ExpressionInterface`
+in methods `select()` and `addSelect()` of your classes that implement `Yiisoft\Db\Query\QueryPartsInterface`.
+
+Add support any scalar values for `$columns` parameter of these methods in your classes that implement
+`Yiisoft\Db\Query\QueryPartsInterface` or inherit `Yiisoft\Db\Query\Query`.
+
 ### Build `Expression` instances inside `Expression::$params`
 
 `ExpressionBuilder` is replaced by an abstract class `AbstractExpressionBuilder` with an instance of the 
diff --git a/src/Query/Query.php b/src/Query/Query.php
index 8321d7a96..d76b16b34 100644
--- a/src/Query/Query.php
+++ b/src/Query/Query.php
@@ -21,6 +21,7 @@
 use function array_shift;
 use function array_unshift;
 use function count;
+use function gettype;
 use function is_array;
 use function is_int;
 use function is_numeric;
@@ -66,9 +67,12 @@
  * ```
  *
  * Query internally uses the {@see \Yiisoft\Db\QueryBuilder\AbstractQueryBuilder} class to generate the SQL statement.
+ *
+ * @psalm-import-type SelectValue from QueryPartsInterface
  */
 class Query implements QueryInterface
 {
+    /** @psalm-var SelectValue $select */
     protected array $select = [];
     protected string|null $selectOption = null;
     protected bool|null $distinct = null;
@@ -178,7 +182,7 @@ public function andHaving(array|string|ExpressionInterface $condition, array $pa
         return $this;
     }
 
-    public function addSelect(array|string|ExpressionInterface $columns): static
+    public function addSelect(array|bool|float|int|string|ExpressionInterface $columns): static
     {
         if ($this->select === []) {
             return $this->select($columns);
@@ -612,7 +616,7 @@ public function scalar(): bool|int|null|string|float
         };
     }
 
-    public function select(array|string|ExpressionInterface $columns, string $option = null): static
+    public function select(array|bool|float|int|string|ExpressionInterface $columns, string $option = null): static
     {
         $this->select = $this->normalizeSelect($columns);
         $this->selectOption = $option;
@@ -854,18 +858,20 @@ private function normalizeOrderBy(array|string|ExpressionInterface $columns): ar
 
     /**
      * Normalizes the `SELECT` columns passed to {@see select()} or {@see addSelect()}.
+     *
+     * @psalm-param SelectValue|scalar|ExpressionInterface $columns
+     * @psalm-return SelectValue
      */
-    private function normalizeSelect(array|ExpressionInterface|string $columns): array
+    private function normalizeSelect(array|bool|float|int|string|ExpressionInterface $columns): array
     {
-        if ($columns instanceof ExpressionInterface) {
-            $columns = [$columns];
-        } elseif (!is_array($columns)) {
-            $columns = preg_split('/\s*,\s*/', trim($columns), -1, PREG_SPLIT_NO_EMPTY);
-        }
+        $columns = match (gettype($columns)) {
+            'array' => $columns,
+            'string' => preg_split('/\s*,\s*/', trim($columns), -1, PREG_SPLIT_NO_EMPTY),
+            default => [$columns],
+        };
 
         $select = [];
 
-        /** @psalm-var array<array-key, ExpressionInterface|string> $columns */
         foreach ($columns as $columnAlias => $columnDefinition) {
             if (is_string($columnAlias)) {
                 // Already in the normalized format, good for them.
@@ -890,8 +896,7 @@ private function normalizeSelect(array|ExpressionInterface|string $columns): arr
                 }
             }
 
-            // Either a string calling a function, DB expression, or sub-query
-            /** @psalm-var string */
+            // Either a string calling a function, instance of ExpressionInterface or a scalar value.
             $select[] = $columnDefinition;
         }
 
diff --git a/src/Query/QueryInterface.php b/src/Query/QueryInterface.php
index 246d007bd..88b3afb8d 100644
--- a/src/Query/QueryInterface.php
+++ b/src/Query/QueryInterface.php
@@ -28,6 +28,7 @@
  * Sorting is supported via {@see orderBy()} and items can be limited to match some conditions using {@see where()}.
  *
  * @psalm-import-type ParamsType from ConnectionInterface
+ * @psalm-import-type SelectValue from QueryPartsInterface
  */
 interface QueryInterface extends ExpressionInterface, QueryPartsInterface, QueryFunctionsInterface
 {
@@ -207,6 +208,7 @@ public function getParams(): array;
 
     /**
      * @return array The "select" value.
+     * @psalm-return SelectValue
      */
     public function getSelect(): array;
 
diff --git a/src/Query/QueryPartsInterface.php b/src/Query/QueryPartsInterface.php
index 9d2b4dec2..9ab460430 100644
--- a/src/Query/QueryPartsInterface.php
+++ b/src/Query/QueryPartsInterface.php
@@ -15,6 +15,7 @@
  *
  * {@see Query} uses these methods to build and manipulate SQL statements.
  *
+ * @psalm-type SelectValue = array<array-key, ExpressionInterface|scalar>
  * @psalm-import-type ParamsType from ConnectionInterface
  */
 interface QueryPartsInterface
@@ -64,11 +65,15 @@ public function addOrderBy(array|string|ExpressionInterface $columns): static;
      * $query->addSelect(["*", "CONCAT(first_name, ' ', last_name) AS full_name"])->one();
      * ```
      *
-     * @param array|ExpressionInterface|string $columns The columns to add to the select.
+     * @param array|ExpressionInterface|scalar $columns The columns to add to the select.
      *
-     * {@see select()} for more details about the format of this parameter.
+     * @see select() for more details about the format of this parameter.
+     *
+     * @since 2.0.0 `$columns` can be a scalar value or an array of scalar values.
+     *
+     * @psalm-param SelectValue|scalar|ExpressionInterface $columns
      */
-    public function addSelect(array|string|ExpressionInterface $columns): static;
+    public function addSelect(array|bool|float|int|string|ExpressionInterface $columns): static;
 
     /**
      * Adds a filtering condition for a specific column and allow the user to choose a filter operator.
@@ -514,7 +519,7 @@ public function rightJoin(array|string $table, array|string $on = '', array $par
     /**
      * Sets the `SELECT` part of the query.
      *
-     * @param array|ExpressionInterface|string $columns The columns to be selected.
+     * @param array|ExpressionInterface|scalar $columns The columns to be selected.
      * Columns can be specified in either a string (for example `id, name`) or an array (such as `['id', 'name']`).
      * Columns can be prefixed with table names (such as `user.id`) and/or contain column aliases
      * (for example `user.id AS user_id`).
@@ -527,8 +532,13 @@ public function rightJoin(array|string $table, array|string $on = '', array $par
      * doesn't need alias, don't use a string key).
      * @param string|null $option More option that should be appended to the 'SELECT' keyword. For example, in MySQL,
      * the option 'SQL_CALC_FOUND_ROWS' can be used.
+     *
+     * @since 2.0.0 `$columns` can be a scalar value or an array of scalar values.
+     * For example, `$query->select(1)` will be converted to `SELECT 1`.
+     *
+     * @psalm-param SelectValue|scalar|ExpressionInterface $columns
      */
-    public function select(array|string|ExpressionInterface $columns, string $option = null): static;
+    public function select(array|bool|float|int|string|ExpressionInterface $columns, string $option = null): static;
 
     /**
      * It allows you to specify more options for the `SELECT` clause of an SQL statement.
diff --git a/src/QueryBuilder/AbstractDQLQueryBuilder.php b/src/QueryBuilder/AbstractDQLQueryBuilder.php
index fd3951540..9119ffa7d 100644
--- a/src/QueryBuilder/AbstractDQLQueryBuilder.php
+++ b/src/QueryBuilder/AbstractDQLQueryBuilder.php
@@ -13,6 +13,7 @@
 use Yiisoft\Db\Expression\Expression;
 use Yiisoft\Db\Expression\ExpressionBuilderInterface;
 use Yiisoft\Db\Expression\ExpressionInterface;
+use Yiisoft\Db\Helper\DbStringHelper;
 use Yiisoft\Db\QueryBuilder\Condition\HashCondition;
 use Yiisoft\Db\QueryBuilder\Condition\Interface\ConditionInterface;
 use Yiisoft\Db\QueryBuilder\Condition\SimpleCondition;
@@ -25,6 +26,7 @@
 use function array_merge;
 use function array_shift;
 use function ctype_digit;
+use function gettype;
 use function implode;
 use function is_array;
 use function is_int;
@@ -324,7 +326,6 @@ public function buildSelect(
             return $select . ' *';
         }
 
-        /** @psalm-var array<array-key, ExpressionInterface|string> $columns */
         foreach ($columns as $i => $column) {
             if ($column instanceof ExpressionInterface) {
                 if (is_int($i)) {
@@ -333,6 +334,16 @@ public function buildSelect(
                     $columns[$i] = $this->buildExpression($column, $params) . ' AS '
                         . $this->quoter->quoteColumnName($i);
                 }
+            } elseif (!is_string($column)) {
+                $columns[$i] = match (gettype($column)) {
+                    'double' => DbStringHelper::normalizeFloat($column),
+                    'boolean' => $column ? 'TRUE' : 'FALSE',
+                    default => (string) $column,
+                };
+
+                if (is_string($i)) {
+                    $columns[$i] .= ' AS ' . $this->quoter->quoteColumnName($i);
+                }
             } elseif (is_string($i) && $i !== $column) {
                 if (!str_contains($column, '(')) {
                     $column = $this->quoter->quoteColumnName($column);
diff --git a/src/QueryBuilder/DQLQueryBuilderInterface.php b/src/QueryBuilder/DQLQueryBuilderInterface.php
index dd2076dbb..6a53585cb 100644
--- a/src/QueryBuilder/DQLQueryBuilderInterface.php
+++ b/src/QueryBuilder/DQLQueryBuilderInterface.php
@@ -11,6 +11,7 @@
 use Yiisoft\Db\Exception\NotSupportedException;
 use Yiisoft\Db\Expression\ExpressionBuilderInterface;
 use Yiisoft\Db\Expression\ExpressionInterface;
+use Yiisoft\Db\Query\QueryPartsInterface;
 use Yiisoft\Db\QueryBuilder\Condition\Interface\ConditionInterface;
 use Yiisoft\Db\Query\QueryInterface;
 
@@ -20,6 +21,7 @@
  * @link https://en.wikipedia.org/wiki/Data_query_language
  *
  * @psalm-import-type ParamsType from ConnectionInterface
+ * @psalm-import-type SelectValue from QueryPartsInterface
  */
 interface DQLQueryBuilderInterface
 {
@@ -224,6 +226,7 @@ public function buildOrderByAndLimit(
      *
      * @return string The `SELECT` clause built from {@see \Yiisoft\Db\Query\Query::select()}.
      *
+     * @psalm-param SelectValue $columns
      * @psalm-param ParamsType $params
      */
     public function buildSelect(
diff --git a/tests/AbstractQueryBuilderTest.php b/tests/AbstractQueryBuilderTest.php
index 4ab4f287f..35cf22c43 100644
--- a/tests/AbstractQueryBuilderTest.php
+++ b/tests/AbstractQueryBuilderTest.php
@@ -2091,6 +2091,24 @@ public function testSelectSubquery(): void
         $this->assertEmpty($params);
     }
 
+    /** @dataProvider \Yiisoft\Db\Tests\Provider\QueryBuilderProvider::selectScalar */
+    public function testSelectScalar(array|bool|float|int|string $columns, string $expected): void
+    {
+        $db = $this->getConnection();
+        $qb = $db->getQueryBuilder();
+
+        $query = (new Query($db))->select($columns);
+
+        [$sql, $params] = $qb->build($query);
+
+        if ($db->getDriverName() === 'oci') {
+            $expected .= ' FROM DUAL';
+        }
+
+        $this->assertSame($expected, $sql);
+        $this->assertEmpty($params);
+    }
+
     public function testSetConditionClasses(): void
     {
         $db = $this->getConnection();
diff --git a/tests/AbstractQueryTest.php b/tests/AbstractQueryTest.php
index 754cab5a3..cae70b93f 100644
--- a/tests/AbstractQueryTest.php
+++ b/tests/AbstractQueryTest.php
@@ -661,6 +661,13 @@ public function testSelect(): void
             ['DISTINCT ON(tour_dates.date_from) tour_dates.date_from', 'tour_dates.id' => 'tour_dates.id'],
             $query->getSelect()
         );
+
+        $query = new Query($db);
+        $query->select(1);
+        $query->addSelect(true);
+        $query->addSelect(['float' => 12.34]);
+
+        $this->assertSame([1, true, 'float' => 12.34], $query->getSelect());
     }
 
     public function testSetJoin(): void
@@ -779,7 +786,7 @@ public function testNormalizeOrderBy(array|string|Expression $columns, array|str
     /**
      * @dataProvider \Yiisoft\Db\Tests\Provider\QueryProvider::normalizeSelect
      */
-    public function testNormalizeSelect(array|string|Expression $columns, array|string $expected): void
+    public function testNormalizeSelect(array|bool|float|int|string|ExpressionInterface $columns, array|string $expected): void
     {
         $query = (new Query($this->getConnection()));
         $this->assertEquals([], $query->getSelect());
diff --git a/tests/Provider/QueryBuilderProvider.php b/tests/Provider/QueryBuilderProvider.php
index 77122b9c9..f8f0b5356 100644
--- a/tests/Provider/QueryBuilderProvider.php
+++ b/tests/Provider/QueryBuilderProvider.php
@@ -1112,6 +1112,22 @@ public static function selectExist(): array
         ];
     }
 
+    public static function selectScalar(): array
+    {
+        return [
+            [1, 'SELECT 1'],
+            ['custom_string', DbHelper::replaceQuotes('SELECT [[custom_string]]', static::$driverName)],
+            [true, 'SELECT TRUE'],
+            [false, 'SELECT FALSE'],
+            [12.34, 'SELECT 12.34'],
+            [[1, true, 12.34], 'SELECT 1, TRUE, 12.34'],
+            [
+                ['a' => 1, 'b' => true, 12.34],
+                DbHelper::replaceQuotes('SELECT 1 AS [[a]], TRUE AS [[b]], 12.34', static::$driverName),
+            ],
+        ];
+    }
+
     public static function update(): array
     {
         return [
diff --git a/tests/Provider/QueryProvider.php b/tests/Provider/QueryProvider.php
index 6833f7f4c..274cf2147 100644
--- a/tests/Provider/QueryProvider.php
+++ b/tests/Provider/QueryProvider.php
@@ -73,6 +73,10 @@ public static function normalizeSelect(): array
                 ['email' => 'email', 'address' => 'address', 'status' => new Expression('1')],
             ],
             [new Expression('1 as Ab'), [new Expression('1 as Ab')]],
+            [1, [1]],
+            [true, [true]],
+            [12.34, [12.34]],
+            [['a' => 1, 'b' => true, 12.34], ['a' => 1, 'b' => true, 12.34]],
         ];
     }
 }