2005 Mutua Madrileña Masters Madrid

{{TennisEventInfo|2005|Mutua Madrileña Masters Madrid|

| date=17–24 October

| edition=4th

| category=ATP Masters Series

| prize_money=$2,200,000

| draw=48S / 16D

| surface=Hard / indoor

| location=Madrid, Spain

| venue=Madrid Arena

| champs= {{flagicon|ESP}} Rafael Nadal{{cite web |title=2005 Madrid – Singles draw |url=https://www.atptour.com/en/scores/archive/madrid/1536/2005/draws?matchtype=singles |publisher=Association of Tennis Professionals (ATP)}}

| champd= {{flagicon|BAH}} Mark Knowles / {{flagicon|CAN}} Daniel Nestor{{cite web |title=2005 Madrid – Doubles draw |url=https://www.atptour.com/en/scores/archive/madrid/1536/2005/draws?matchtype=doubles |publisher=Association of Tennis Professionals (ATP)}}

| main_name=Madrid Open (tennis){{!}}Madrid Open

}}

The 2005 Madrid Masters (also known as the Mutua Madrileña Masters Madrid for sponsorship reasons) was a tennis tournament played on indoor hard courts. It was the 4th edition of the Madrid Masters, and was part of the ATP Masters Series of the 2005 ATP Tour. It took place at the Madrid Arena in Madrid, Spain, from 17 October through 24 October 2005. First-seeded Rafael Nadal won the singles title.

The singles field was led by World No. 2 Rafael Nadal. Other top seeds were Andy Roddick and Nikolay Davydenko.