diff --git a/config/set/code-quality/code-quality.yaml b/config/set/code-quality/code-quality.yaml
index 6965e49270a3..6f5f45747b6b 100644
--- a/config/set/code-quality/code-quality.yaml
+++ b/config/set/code-quality/code-quality.yaml
@@ -25,6 +25,7 @@ services:
     Rector\CodeQuality\Rector\If_\ConsecutiveNullCompareReturnsToNullCoalesceQueueRector: null
     Rector\CodeQuality\Rector\If_\SimplifyIfIssetToNullCoalescingRector: null
     Rector\CodeQuality\Rector\If_\ExplicitBoolCompareRector: null
+    Rector\CodeQuality\Rector\If_\CombineIfRector: null
     Rector\CodeQuality\Rector\Equal\UseIdenticalOverEqualWithSameTypeRector: null
     Rector\CodeQuality\Rector\Ternary\SimplifyDuplicatedTernaryRector: null
     Rector\CodeQuality\Rector\Identical\SimplifyBoolIdenticalTrueRector: null
diff --git a/docs/AllRectorsOverview.md b/docs/AllRectorsOverview.md
index 294121d32659..2a8268a0b667 100644
--- a/docs/AllRectorsOverview.md
+++ b/docs/AllRectorsOverview.md
@@ -1,4 +1,4 @@
-# All 429 Rectors Overview
+# All 430 Rectors Overview
 
 - [Projects](#projects)
 - [General](#general)
@@ -514,6 +514,29 @@ Change array_push() to direct variable assign
 
 <br>
 
+### `CombineIfRector`
+
+- class: `Rector\CodeQuality\Rector\If_\CombineIfRector`
+
+Merges nested if statements
+
+```diff
+ class SomeClass {
+     public function run()
+     {
+-        if ($cond1) {
+-            if ($cond2) {
+-                return 'foo';
+-            }
++        if ($cond1 && $cond2) {
++            return 'foo';
+         }
+     }
+ }
+```
+
+<br>
+
 ### `CombinedAssignRector`
 
 - class: `Rector\CodeQuality\Rector\Assign\CombinedAssignRector`
diff --git a/packages/CodeQuality/src/Rector/If_/CombineIfRector.php b/packages/CodeQuality/src/Rector/If_/CombineIfRector.php
new file mode 100644
index 000000000000..2577d6b2b299
--- /dev/null
+++ b/packages/CodeQuality/src/Rector/If_/CombineIfRector.php
@@ -0,0 +1,102 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\CodeQuality\Rector\If_;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\BinaryOp\BooleanAnd;
+use PhpParser\Node\Stmt\If_;
+use Rector\Rector\AbstractRector;
+use Rector\RectorDefinition\CodeSample;
+use Rector\RectorDefinition\RectorDefinition;
+
+/**
+ * @see \Rector\CodeQuality\Tests\Rector\If_\CombineIfRector\CombineIfRectorTest
+ */
+final class CombineIfRector extends AbstractRector
+{
+    public function getDefinition(): RectorDefinition
+    {
+        return new RectorDefinition('Merges nested if statements', [
+            new CodeSample(
+                <<<'PHP'
+class SomeClass {
+    public function run()
+    {
+        if ($cond1) {
+            if ($cond2) {
+                return 'foo';
+            }
+        }
+    }
+}
+PHP
+                ,
+                <<<'PHP'
+class SomeClass {
+    public function run()
+    {
+        if ($cond1 && $cond2) {
+            return 'foo';
+        }
+    }
+}
+PHP
+
+            ),
+        ]);
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getNodeTypes(): array
+    {
+        return [If_::class];
+    }
+
+    /**
+     * @param If_ $node
+     */
+    public function refactor(Node $node): ?Node
+    {
+        if ($this->shouldSkip($node)) {
+            return null;
+        }
+
+        /** @var Node\Stmt\If_ $subIf */
+        $subIf = $node->stmts[0];
+        $node->cond = new BooleanAnd($node->cond, $subIf->cond);
+        $node->stmts = $subIf->stmts;
+        return $node;
+    }
+
+    private function shouldSkip(If_ $node): bool
+    {
+        if ($node->else !== null) {
+            return true;
+        }
+
+        if (count($node->stmts) !== 1) {
+            return true;
+        }
+
+        if ($node->elseifs) {
+            return true;
+        }
+
+        if (! $node->stmts[0] instanceof If_) {
+            return true;
+        }
+
+        if ($node->stmts[0]->else !== null) {
+            return true;
+        }
+
+        if ($node->stmts[0]->elseifs) {
+            return true;
+        }
+        return false;
+    }
+}
diff --git a/packages/CodeQuality/tests/Rector/If_/CombineIfRector/CombineIfRectorTest.php b/packages/CodeQuality/tests/Rector/If_/CombineIfRector/CombineIfRectorTest.php
new file mode 100644
index 000000000000..153c11dd5c0f
--- /dev/null
+++ b/packages/CodeQuality/tests/Rector/If_/CombineIfRector/CombineIfRectorTest.php
@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\CodeQuality\Tests\Rector\If_\CombineIfRector;
+
+use Iterator;
+use Rector\CodeQuality\Rector\If_\CombineIfRector;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+
+final class CombineIfRectorTest extends AbstractRectorTestCase
+{
+    /**
+     * @dataProvider provideDataForTest()
+     */
+    public function test(string $file): void
+    {
+        $this->doTestFile($file);
+    }
+
+    public function provideDataForTest(): Iterator
+    {
+        return $this->yieldFilesFromDirectory(__DIR__ . '/Fixture');
+    }
+
+    protected function getRectorClass(): string
+    {
+        return CombineIfRector::class;
+    }
+}
diff --git a/packages/CodeQuality/tests/Rector/If_/CombineIfRector/Fixture/child_else.php.inc b/packages/CodeQuality/tests/Rector/If_/CombineIfRector/Fixture/child_else.php.inc
new file mode 100644
index 000000000000..a8bb998e3e13
--- /dev/null
+++ b/packages/CodeQuality/tests/Rector/If_/CombineIfRector/Fixture/child_else.php.inc
@@ -0,0 +1,16 @@
+<?php
+
+namespace Rector\CodeQuality\Tests\Rector\If_\CombineIfRector\ChildElse;
+
+class SomeClass {
+    public function run()
+    {
+        if ($cond1) {
+            if ($cond2) {
+                return 'foo';
+            } else {
+                return 'bar';
+            }
+        }
+    }
+}
diff --git a/packages/CodeQuality/tests/Rector/If_/CombineIfRector/Fixture/child_elseif.php.inc b/packages/CodeQuality/tests/Rector/If_/CombineIfRector/Fixture/child_elseif.php.inc
new file mode 100644
index 000000000000..4afeb0885509
--- /dev/null
+++ b/packages/CodeQuality/tests/Rector/If_/CombineIfRector/Fixture/child_elseif.php.inc
@@ -0,0 +1,16 @@
+<?php
+
+namespace Rector\CodeQuality\Tests\Rector\If_\CombineIfRector\ChildElseIf;
+
+class SomeClass {
+    public function run()
+    {
+        if ($cond1) {
+            if ($cond2) {
+                return 'foo';
+            } elseif($cond3) {
+                return 'bar';
+            }
+        }
+    }
+}
diff --git a/packages/CodeQuality/tests/Rector/If_/CombineIfRector/Fixture/fixture.php.inc b/packages/CodeQuality/tests/Rector/If_/CombineIfRector/Fixture/fixture.php.inc
new file mode 100644
index 000000000000..d267b1c5a824
--- /dev/null
+++ b/packages/CodeQuality/tests/Rector/If_/CombineIfRector/Fixture/fixture.php.inc
@@ -0,0 +1,31 @@
+<?php
+
+namespace Rector\CodeQuality\Tests\Rector\If_\CombineIfRector\Fixture;
+
+class SomeClass {
+    public function run()
+    {
+        if ($cond1) {
+            if ($cond2) {
+                return 'foo';
+            }
+        }
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\CodeQuality\Tests\Rector\If_\CombineIfRector\Fixture;
+
+class SomeClass {
+    public function run()
+    {
+        if ($cond1 && $cond2) {
+            return 'foo';
+        }
+    }
+}
+
+?>
diff --git a/packages/CodeQuality/tests/Rector/If_/CombineIfRector/Fixture/more_statements.php.inc b/packages/CodeQuality/tests/Rector/If_/CombineIfRector/Fixture/more_statements.php.inc
new file mode 100644
index 000000000000..459a82d7101a
--- /dev/null
+++ b/packages/CodeQuality/tests/Rector/If_/CombineIfRector/Fixture/more_statements.php.inc
@@ -0,0 +1,17 @@
+<?php
+
+namespace Rector\CodeQuality\Tests\Rector\If_\CombineIfRector\MoreStatements;
+
+class SomeClass {
+    public function run()
+    {
+        if ($cond1) {
+            if ($cond2) {
+                return 'foo';
+            }
+            return 'bar';
+        }
+    }
+}
+
+?>
diff --git a/packages/CodeQuality/tests/Rector/If_/CombineIfRector/Fixture/parent_else.php.inc b/packages/CodeQuality/tests/Rector/If_/CombineIfRector/Fixture/parent_else.php.inc
new file mode 100644
index 000000000000..7606bf6fe425
--- /dev/null
+++ b/packages/CodeQuality/tests/Rector/If_/CombineIfRector/Fixture/parent_else.php.inc
@@ -0,0 +1,16 @@
+<?php
+
+namespace Rector\CodeQuality\Tests\Rector\If_\CombineIfRector\ParentElse;
+
+class SomeClass {
+    public function run()
+    {
+        if ($cond1) {
+            if ($cond2) {
+                return 'foo';
+            }
+        } else {
+            return 'bar';
+        }
+    }
+}
diff --git a/packages/CodeQuality/tests/Rector/If_/CombineIfRector/Fixture/parent_elseif.php.inc b/packages/CodeQuality/tests/Rector/If_/CombineIfRector/Fixture/parent_elseif.php.inc
new file mode 100644
index 000000000000..dc4adf04636f
--- /dev/null
+++ b/packages/CodeQuality/tests/Rector/If_/CombineIfRector/Fixture/parent_elseif.php.inc
@@ -0,0 +1,16 @@
+<?php
+
+namespace Rector\CodeQuality\Tests\Rector\If_\CombineIfRector\ParentElseIf;
+
+class SomeClass {
+    public function run()
+    {
+        if ($cond1) {
+            if ($cond2) {
+                return 'foo';
+            }
+        } elseif($cond3) {
+            return 'bar';
+        }
+    }
+}