diff --git a/packages/ckeditor5-table/src/converters/upcasttable.ts b/packages/ckeditor5-table/src/converters/upcasttable.ts
index 2c5fc63bc2b..3de4dd2f860 100644
--- a/packages/ckeditor5-table/src/converters/upcasttable.ts
+++ b/packages/ckeditor5-table/src/converters/upcasttable.ts
@@ -241,14 +241,26 @@ function scanTable( viewTable: ViewElement ) {
 			( el: ViewNode ): el is ViewElement & { name: 'tr' } => el.is( 'element', 'tr' )
 		);
 
+		// Keep tracking of the previous row columns count to improve detection of heading rows.
+		let maxPrevColumns = null;
+
 		for ( const tr of trs ) {
+			const trColumns = Array
+				.from( tr.getChildren() )
+				.filter( el => el.is( 'element', 'td' ) || el.is( 'element', 'th' ) );
+
 			// This <tr> is a child of a first <thead> element.
 			if (
 				( firstTheadElement && tableChild === firstTheadElement ) ||
 				(
 					tableChild.name === 'tbody' &&
-					Array.from( tr.getChildren() ).length &&
-					Array.from( tr.getChildren() ).every( e => e.is( 'element', 'th' ) )
+					trColumns.length > 0 &&
+					// These conditions handles the case when the first column is a <th> element and it's the only column in the row.
+					// This case is problematic because it's not clear if this row should be a heading row or not, as it may be result
+					// of the cell span from the previous row.
+					// Issue: https://github.com/ckeditor/ckeditor5/issues/17556
+					( maxPrevColumns === null || trColumns.length === maxPrevColumns ) &&
+					trColumns.every( e => e.is( 'element', 'th' ) )
 				)
 			) {
 				headingRows++;
@@ -263,6 +275,11 @@ function scanTable( viewTable: ViewElement ) {
 					headingColumns = headingCols;
 				}
 			}
+
+			// We use the maximum number of columns to avoid false positives when detecting
+			// multiple rows with single column within `rowspan`. Without it the last row of `rowspan=3`
+			// would be detected as a heading row because it has only one column (identical to the previous row).
+			maxPrevColumns = Math.max( maxPrevColumns || 0, trColumns.length );
 		}
 	}
 
diff --git a/packages/ckeditor5-table/tests/converters/upcasttable.js b/packages/ckeditor5-table/tests/converters/upcasttable.js
index 0bf5af058ac..1744d6cd4cc 100644
--- a/packages/ckeditor5-table/tests/converters/upcasttable.js
+++ b/packages/ckeditor5-table/tests/converters/upcasttable.js
@@ -562,7 +562,7 @@ describe( 'upcastTable()', () => {
 	} );
 
 	describe( 'headingRows', () => {
-		it( 'should be able to detect heding row in 2x2 table', () => {
+		it( 'should be able to detect heading row in 2x2 table', () => {
 			editor.setData(
 				'<table>' +
 					'<tr>' +
@@ -590,7 +590,7 @@ describe( 'upcastTable()', () => {
 			);
 		} );
 
-		it( 'should be able to detect heding row in table with caption', () => {
+		it( 'should be able to detect heading row in table with caption', () => {
 			editor.setData(
 				'<table>' +
 					'<caption>Concerts</caption>' +
@@ -645,7 +645,7 @@ describe( 'upcastTable()', () => {
 			);
 		} );
 
-		it( 'should be able to detect heding row in 2x1 table', () => {
+		it( 'should be able to detect heading row in 2x1 table', () => {
 			editor.setData(
 				'<table>' +
 					'<tbody>' +
@@ -671,7 +671,7 @@ describe( 'upcastTable()', () => {
 			);
 		} );
 
-		it( 'should be able to detect heding row that has colspan', () => {
+		it( 'should be able to detect heading row that has colspan', () => {
 			editor.setData(
 				'<table>' +
 					'<tbody>' +
@@ -700,6 +700,108 @@ describe( 'upcastTable()', () => {
 				'</table>'
 			);
 		} );
+
+		it( 'should not treat the row containing only th as a heading row if it follows rowspan=2', () => {
+			editor.setData(
+				'<table>' +
+					'<tbody>' +
+						'<tr>' +
+							'<th>00</th>' +
+							'<td>01</td>' +
+							'<td>02</td>' +
+						'</tr>' +
+						'<tr>' +
+							'<th>10</th>' +
+							'<td colspan="2" rowspan="2">11</td>' +
+						'</tr>' +
+						'<tr>' +
+							'<th>20</th>' +
+						'</tr>' +
+						'<tr>' +
+							'<th>30</th>' +
+							'<td>31</td>' +
+							'<td>32</td>' +
+						'</tr>' +
+					'</tbody>' +
+				'</table>'
+			);
+
+			expectModel(
+				'<table headingColumns="1">' +
+					'<tableRow>' +
+						'<tableCell><paragraph>00</paragraph></tableCell>' +
+						'<tableCell><paragraph>01</paragraph></tableCell>' +
+						'<tableCell><paragraph>02</paragraph></tableCell>' +
+					'</tableRow>' +
+					'<tableRow>' +
+						'<tableCell><paragraph>10</paragraph></tableCell>' +
+						'<tableCell colspan="2" rowspan="2"><paragraph>11</paragraph></tableCell>' +
+					'</tableRow>' +
+					'<tableRow>' +
+						'<tableCell><paragraph>20</paragraph></tableCell>' +
+					'</tableRow>' +
+					'<tableRow>' +
+						'<tableCell><paragraph>30</paragraph></tableCell>' +
+						'<tableCell><paragraph>31</paragraph></tableCell>' +
+						'<tableCell><paragraph>32</paragraph></tableCell>' +
+					'</tableRow>' +
+				'</table>'
+			);
+		} );
+
+		it( 'should not treat the row containing only th as a heading row if it is last row of rowspan=3', () => {
+			editor.setData(
+				'<table>' +
+					'<tbody>' +
+						'<tr>' +
+							'<th>00</th>' +
+							'<td>01</td>' +
+							'<td>02</td>' +
+						'</tr>' +
+						'<tr>' +
+							'<th>10</th>' +
+							'<td colspan="2" rowspan="3">11</td>' +
+						'</tr>' +
+						'<tr>' +
+							'<th>20</th>' +
+						'</tr>' +
+						'<tr>' +
+							'<th>30</th>' +
+						'</tr>' +
+						'<tr>' +
+							'<th>40</th>' +
+							'<td>41</td>' +
+							'<td>42</td>' +
+						'</tr>' +
+					'</tbody>' +
+				'</table>'
+			);
+
+			expectModel(
+				'<table headingColumns="1">' +
+					'<tableRow>' +
+						'<tableCell><paragraph>00</paragraph></tableCell>' +
+						'<tableCell><paragraph>01</paragraph></tableCell>' +
+						'<tableCell><paragraph>02</paragraph></tableCell>' +
+					'</tableRow>' +
+					'<tableRow>' +
+						'<tableCell><paragraph>10</paragraph></tableCell>' +
+						'<tableCell colspan="2" rowspan="3"><paragraph>11</paragraph></tableCell>' +
+					'</tableRow>' +
+					'<tableRow>' +
+						'<tableCell><paragraph>20</paragraph></tableCell>' +
+					'</tableRow>' +
+					'<tableRow>' +
+						'<tableCell><paragraph>30</paragraph></tableCell>' +
+					'</tableRow>' +
+					'<tableRow>' +
+						'<tableCell><paragraph>40</paragraph></tableCell>' +
+						'<tableCell><paragraph>41</paragraph></tableCell>' +
+						'<tableCell><paragraph>42</paragraph></tableCell>' +
+					'</tableRow>' +
+				'</table>'
+			);
+		} );
 	} );
 
 	describe( 'block contents', () => {