diff --git a/CHANGELOG.md b/CHANGELOG.md
index b032124f9..97b2309d3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- Shift+Arrow in the data grid now starts and extends a cell selection from the focused cell, instead of doing nothing until a range already existed. Cmd+Shift+Arrow extends to the row or column edge.
 - Delete key now respects cell-range selection in the data grid, removing all rows covered by the selection instead of ignoring it.
 - Right-clicking inside a multi-row or cell-range selection no longer collapses the selection before the context menu appears.
 - Oracle connections no longer crash the app during connect. A short or unexpected handshake packet from the server (such as session-setup metadata or an error) now surfaces the error or continues instead of trapping. (#1683)
diff --git a/TablePro/Views/Results/KeyHandlingTableView.swift b/TablePro/Views/Results/KeyHandlingTableView.swift
index 365d0c7a9..d9b92c23d 100644
--- a/TablePro/Views/Results/KeyHandlingTableView.swift
+++ b/TablePro/Views/Results/KeyHandlingTableView.swift
@@ -321,24 +321,16 @@ final class KeyHandlingTableView: NSTableView {
 
         switch key {
         case .leftArrow:
-            handleHorizontalArrow(direction: .left, modifiers: modifiers, currentRow: row)
+            handleArrow(.left, modifiers: modifiers, currentRow: row, event: event)
             return
         case .rightArrow:
-            handleHorizontalArrow(direction: .right, modifiers: modifiers, currentRow: row)
+            handleArrow(.right, modifiers: modifiers, currentRow: row, event: event)
             return
         case .upArrow:
-            if modifiers.contains(.shift) {
-                gridSelection?.extendActiveCell(direction: .up, jumpToEdge: modifiers.contains(.command), totalRows: totalRows(), totalColumns: totalDataColumns())
-                return
-            }
-            super.keyDown(with: event)
+            handleArrow(.up, modifiers: modifiers, currentRow: row, event: event)
             return
         case .downArrow:
-            if modifiers.contains(.shift) {
-                gridSelection?.extendActiveCell(direction: .down, jumpToEdge: modifiers.contains(.command), totalRows: totalRows(), totalColumns: totalDataColumns())
-                return
-            }
-            super.keyDown(with: event)
+            handleArrow(.down, modifiers: modifiers, currentRow: row, event: event)
             return
         case .home, .end, .pageUp, .pageDown:
             super.keyDown(with: event)
@@ -378,18 +370,41 @@ final class KeyHandlingTableView: NSTableView {
         return combo.matches(event)
     }
 
-    private func handleHorizontalArrow(direction: GridSelectionController.Direction, modifiers: NSEvent.ModifierFlags, currentRow: Int) {
-        if modifiers.contains(.shift), let controller = gridSelection, !controller.isEmpty {
-            controller.extendActiveCell(direction: direction, jumpToEdge: modifiers.contains(.command), totalRows: totalRows(), totalColumns: totalDataColumns())
+    private func handleArrow(_ direction: GridSelectionController.Direction, modifiers: NSEvent.ModifierFlags, currentRow: Int, event: NSEvent) {
+        if modifiers.contains(.shift) {
+            if extendGridSelection(direction: direction, jumpToEdge: modifiers.contains(.command)) {
+                return
+            }
+            super.keyDown(with: event)
             return
         }
+        gridSelection?.clear()
         switch direction {
         case .left: handleLeftArrow(currentRow: currentRow)
         case .right: handleRightArrow(currentRow: currentRow)
-        default: break
+        case .up, .down: super.keyDown(with: event)
         }
     }
 
+    private func extendGridSelection(direction: GridSelectionController.Direction, jumpToEdge: Bool) -> Bool {
+        guard let controller = gridSelection else { return false }
+        let seed = controller.isEmpty ? focusedGridCoord() : nil
+        guard !controller.isEmpty || seed != nil else { return false }
+        controller.extendActiveCell(
+            from: seed,
+            direction: direction,
+            jumpToEdge: jumpToEdge,
+            totalRows: totalRows(),
+            totalColumns: totalDataColumns()
+        )
+        return true
+    }
+
+    private func focusedGridCoord() -> GridCoord? {
+        guard let cell = focusedDataCell() else { return nil }
+        return GridCoord(row: cell.row, column: cell.columnIndex)
+    }
+
     @objc override func insertNewline(_ sender: Any?) {
         let row = selectedRow
         guard row >= 0,
diff --git a/TablePro/Views/Results/Selection/GridSelectionController.swift b/TablePro/Views/Results/Selection/GridSelectionController.swift
index aacff4dcd..ca300ea0c 100644
--- a/TablePro/Views/Results/Selection/GridSelectionController.swift
+++ b/TablePro/Views/Results/Selection/GridSelectionController.swift
@@ -159,10 +159,10 @@ final class GridSelectionController {
         update(.single(rect, anchor: anchor, active: anchor))
     }
 
-    func extendActiveCell(direction: Direction, jumpToEdge: Bool, totalRows: Int, totalColumns: Int) {
-        guard let active = selection.activeCell else { return }
+    func extendActiveCell(from seed: GridCoord? = nil, direction: Direction, jumpToEdge: Bool, totalRows: Int, totalColumns: Int) {
+        guard let active = selection.activeCell ?? seed else { return }
+        let origin = selection.anchor ?? seed ?? active
         let next = step(from: active, direction: direction, jumpToEdge: jumpToEdge, totalRows: totalRows, totalColumns: totalColumns)
-        let origin = selection.anchor ?? active
         update(.single(GridRect.between(origin, next), anchor: origin, active: next))
     }
 
diff --git a/TableProTests/Views/Results/CellSelectionTests.swift b/TableProTests/Views/Results/CellSelectionTests.swift
index cf83d74b1..980eb42eb 100644
--- a/TableProTests/Views/Results/CellSelectionTests.swift
+++ b/TableProTests/Views/Results/CellSelectionTests.swift
@@ -291,13 +291,84 @@ struct GridSelectionControllerTests {
         #expect(controller.selection.rectangles == [GridRect(rows: 2...2, columns: 2...9)])
     }
 
-    @Test("extendActiveCell is a no-op when the selection is empty")
+    @Test("extendActiveCell without a seed is a no-op when the selection is empty")
     func extendActiveCellNoOpEmpty() {
         let controller = GridSelectionController()
         controller.extendActiveCell(direction: .down, jumpToEdge: false, totalRows: 10, totalColumns: 10)
         #expect(controller.selection.isEmpty)
     }
 
+    @Test("extendActiveCell with a seed begins a range anchored at the focused cell")
+    func extendActiveCellSeedsFromFocusedCell() {
+        let controller = GridSelectionController()
+        let focused = GridCoord(row: 3, column: 4)
+
+        controller.extendActiveCell(from: focused, direction: .down, jumpToEdge: false, totalRows: 10, totalColumns: 10)
+
+        #expect(controller.selection.rectangles == [GridRect(rows: 3...4, columns: 4...4)])
+        #expect(controller.selection.anchor == focused)
+        #expect(controller.selection.activeCell == GridCoord(row: 4, column: 4))
+    }
+
+    @Test("a seeded extend grows by one cell in each direction from the focused cell")
+    func extendActiveCellSeedsInEveryDirection() {
+        let focused = GridCoord(row: 3, column: 3)
+        let cases: [(GridSelectionController.Direction, GridRect, GridCoord)] = [
+            (.up, GridRect(rows: 2...3, columns: 3...3), GridCoord(row: 2, column: 3)),
+            (.down, GridRect(rows: 3...4, columns: 3...3), GridCoord(row: 4, column: 3)),
+            (.left, GridRect(rows: 3...3, columns: 2...3), GridCoord(row: 3, column: 2)),
+            (.right, GridRect(rows: 3...3, columns: 3...4), GridCoord(row: 3, column: 4))
+        ]
+        for (direction, expectedRect, expectedActive) in cases {
+            let controller = GridSelectionController()
+            controller.extendActiveCell(from: focused, direction: direction, jumpToEdge: false, totalRows: 10, totalColumns: 10)
+            #expect(controller.selection.rectangles == [expectedRect])
+            #expect(controller.selection.anchor == focused)
+            #expect(controller.selection.activeCell == expectedActive)
+        }
+    }
+
+    @Test("repeated seeded extend keeps the anchor fixed and reverses by shrinking")
+    func extendActiveCellAnchorStaysFixedOnReverse() {
+        let controller = GridSelectionController()
+        let focused = GridCoord(row: 2, column: 2)
+
+        controller.extendActiveCell(from: focused, direction: .down, jumpToEdge: false, totalRows: 10, totalColumns: 10)
+        controller.extendActiveCell(direction: .down, jumpToEdge: false, totalRows: 10, totalColumns: 10)
+        #expect(controller.selection.rectangles == [GridRect(rows: 2...4, columns: 2...2)])
+
+        controller.extendActiveCell(direction: .up, jumpToEdge: false, totalRows: 10, totalColumns: 10)
+        #expect(controller.selection.rectangles == [GridRect(rows: 2...3, columns: 2...2)])
+        #expect(controller.selection.anchor == focused)
+        #expect(controller.selection.activeCell == GridCoord(row: 3, column: 2))
+    }
+
+    @Test("a seeded extend with jumpToEdge runs from the focused cell to the grid edge")
+    func extendActiveCellSeedsToEdge() {
+        let controller = GridSelectionController()
+        let focused = GridCoord(row: 2, column: 2)
+
+        controller.extendActiveCell(from: focused, direction: .right, jumpToEdge: true, totalRows: 10, totalColumns: 10)
+
+        #expect(controller.selection.rectangles == [GridRect(rows: 2...2, columns: 2...9)])
+        #expect(controller.selection.anchor == focused)
+        #expect(controller.selection.activeCell == GridCoord(row: 2, column: 9))
+    }
+
+    @Test("the seed is ignored when a selection already exists")
+    func extendActiveCellIgnoresSeedWhenSelectionExists() {
+        let controller = GridSelectionController()
+        let origin = GridCoord(row: 2, column: 2)
+        _ = controller.beginDrag(at: origin, modifiers: [])
+        controller.continueDrag(to: origin)
+        controller.endDrag(dragged: true, originalCoord: origin)
+
+        controller.extendActiveCell(from: GridCoord(row: 9, column: 9), direction: .down, jumpToEdge: false, totalRows: 10, totalColumns: 10)
+
+        #expect(controller.selection.rectangles == [GridRect(rows: 2...3, columns: 2...2)])
+        #expect(controller.selection.anchor == origin)
+    }
+
     @Test("clear empties the selection")
     func clearEmpties() {
         let controller = GridSelectionController()