diff --git a/pcsx2/GS/Renderers/SW/GSRendererSW.cpp b/pcsx2/GS/Renderers/SW/GSRendererSW.cpp
index bd73ecde2a..4fc316e825 100644
--- a/pcsx2/GS/Renderers/SW/GSRendererSW.cpp
+++ b/pcsx2/GS/Renderers/SW/GSRendererSW.cpp
@@ -1231,9 +1231,10 @@ bool GSRendererSW::GetScanlineGlobalData(SharedData* data)
 					gd.t.mask.U32[0] = 0;
 					break;
 				case CLAMP_REGION_CLAMP:
-					// REGION_CLAMP ignores the actual texture size
-					gd.t.min.U16[0] = gd.t.minmax.U16[0] = context->CLAMP.MINU;
-					gd.t.max.U16[0] = gd.t.minmax.U16[2] = context->CLAMP.MAXU;
+					// REGION_CLAMP ignores the actual texture size, but tw is already optimised in GetFixedTEX0Size.
+					// It's important we don't go off MAXU (if bigger) here as the sw renderer can attempt to draw pixels outside the triangle which can cause out of bounds issues.
+					gd.t.min.U16[0] = gd.t.minmax.U16[0] = std::min<u16>(context->CLAMP.MINU, tw - 1);
+					gd.t.max.U16[0] = gd.t.minmax.U16[2] = std::min<u16>(context->CLAMP.MAXU, tw - 1);
 					gd.t.mask.U32[0] = 0;
 					break;
 				case CLAMP_REGION_REPEAT:
@@ -1259,9 +1260,10 @@ bool GSRendererSW::GetScanlineGlobalData(SharedData* data)
 					gd.t.mask.U32[2] = 0;
 					break;
 				case CLAMP_REGION_CLAMP:
-					// REGION_CLAMP ignores the actual texture size
-					gd.t.min.U16[4] = gd.t.minmax.U16[1] = context->CLAMP.MINV;
-					gd.t.max.U16[4] = gd.t.minmax.U16[3] = context->CLAMP.MAXV; // ffx anima summon scene, when the anchor appears (th = 256, maxv > 256)
+					// REGION_CLAMP ignores the actual texture size, but th is already optimised in GetFixedTEX0Size
+					// It's important we don't go off MAXV (if bigger) here as the sw renderer can attempt to draw pixels outside the triangle which can cause out of bounds issues.
+					gd.t.min.U16[4] = gd.t.minmax.U16[1] = std::min<u16>(context->CLAMP.MINV, th - 1);
+					gd.t.max.U16[4] = gd.t.minmax.U16[3] = std::min<u16>(context->CLAMP.MAXV, th - 1); // ffx anima summon scene, when the anchor appears (th = 256, maxv > 256)
 					gd.t.mask.U32[2] = 0;
 					break;
 				case CLAMP_REGION_REPEAT: