The 100 metres at the 2004 Summer Olympics as part of the athletics program were held at the Athens Olympic Stadium, August 21 to August 22.

The top three runners in each of the initial ten heats automatically qualified for the second round. The next ten fastest runners from across the heats also qualified. Those 40 runners competed in 5 heats in the second round, with the top three runners from each heat and the single next fastest runner qualifying for the semifinals. There were two semifinal heats, and only the top four from each heat advanced to the final.

Records

Medals

Justin Gatlin, United States	Francis Obikwelu, Portugal	Maurice Greene, United States

Qualification

The qualification period for Athletics was 1 January 2003 to 9 August 2004. For the men's 100 metres, each National Olympic Committee was permitted to enter up to three athletes that had run the race in 10.21 seconds or faster during the qualification period. If an NOC had no athletes that qualified under that standard, one athlete that had run the race in 10.28 seconds or faster could be entered.

Going into the event, the top ten International Association of Athletics Federations ranked athletes were:

Results

All times shown are in seconds.
Q denotes qualification by place.
q denotes qualification by time.
DNS denotes did not start.
DNF denotes did not finish.
AR denotes area record
NR denotes national record.
PB denotes personal best.
SB denotes season's best.

Round 1

August 21

Round 1, Heat 1

1. Frank Fredericks, Namibia 10.12 s Q SB
2. Uchenna Emedolu, Nigeria 10.22 s Q
3. Shingo Suetsugu, Japan 10.27 s Q
4. Darren Campbell, Great Britain 10.35 s
5. Chen Haijian, China 10.45 s
6. Eric Nkansah, Ghana 10.54 s
7. Poh Seng Song, Singapore 10.75 s
8. Yazaldes Nascimento, São Tomé and Príncipe 11.00 s

Round 1, Heat 2

1. Mark Lewis-Francis, Great Britain 10.13 s Q SB
2. Aziz Zakari, Ghana 10.19 s Q
3. Roland Nemeth, Hungary 10.28 s Q
4. Salem Mubarak Al Yami, Saudi Arabia 10.36 s
5. Darren Gilford, Malta 10.67 s
6. Khalil Al Hanahneh, Jordan 10.76 s
7. Kakianako Nariki, Kiribati 11.62 s

• Marc Burns, Trinidad and Tobago Disqualified - false start

Round 1, Heat 3

1. Justin Gatlin, United States 10.07 s Q
2. Kareem Streete-Thompson, Cayman Islands 10.15 s Q SB
3. Leonard Myles-Mills, Ghana 10.21 s Q SB
4. Vicente de Lima, Brazil 10.23 s
5. Andrey Yepishin, Russia 10.29 s
6. Yeoryios Theodoridis, Greece 10.32 s
7. Hadhari Djaffar, Comoros 10.62 s
8. Sultan Saeed, Maldives 11.72 s

• Juan Sainfleur, Dominican Republic DNF

Round 1, Heat 4

1. Shawn Crawford, United States 10.02 s Q
2. Obadele Thompson, Barbados 10.08 s Q SB
3. Matic Osovnikar, Slovenia 10.15 s Q NR
4. Idrissa Sanou, Burkina Faso 10.33 s
5. Diego Ferreira, Paraguay 10.50 s NB
6. Pierre de Windt , Aruba 11.02 s
7. Chamleunesouk Ao Oudomphonh, Laos 11.30 s
8. Masound Azizi , Afghanistan 11.66 s

• Hristoforos Hoidis , Greece DNS

Round 1, Heat 5

1. Francis Obikwelu, Portugal 10.09 s Q
2. Ronald Pognon , France 10.18s - Q
3. Jaysuma Saidy Ndure , Gambia 10.26 s Q NR
4. Jarbas Mascarenhas , Brazil 10.34 s
5. Hiroyasu Tsuchie , Japan 10.37 s
6. Adrian Durant , Virgin Islands 10.52 s
7. Nabie Foday Fofanah , Guinea 10.62 s
8. Harmon Harmon , Cook Islands 11.22 s PB

Round 1, Heat 6

1. Nobuharu Asahara , Japan 10.33 s Q
2. Lukasz Chyla , Poland 10.35 s Q
3. Eric Pacome N'Dri, Côte d'Ivoire 10.39 s Q
4. Ato Boldon, Trinidad and Tobago 10.41 s
5. Issa Aime Nthepe , France 10.67 s
6. Gabor Dobos , Hungary 10.68 s
7. John Howard , Federated States of Micronesia 10.85 s NR
8. Mohammad Shamsuddin , Bangladesh 11.13 s

Round 1, Heat 7

1. Asafa Powell, Jamaica 10.06 s Q
2. Jason Gardener, Great Britain 10.15 s Q SB
3. Joshua Ross , Australia 10.24 s Q PB
4. Andre Domingos , Brazil 10.28 s
5. Pierre Browne , Canada 10.32 s
6. Lamin Tucker , Sierra Leone 10.72 s
7. Kelsey Nakanelua , American Samoa 11.25 s
8. Sopheak Phouk , Cambodia 11.56 s PB
9. Djikoloum Mobele , Chad DNS

Round 1, Heat 8

1. Maurice Greene, United States 10.18 s Q
2. Dwight Thomas , Jamaica 10.21s - Q
3. Churandy Martina , Netherlands Antilles 10.23 s Q
4. Alexander Kosenkow , Germany 10.28 s
5. Prodromos Katsantonis , Cyprus 10.50 s SB
6. Wai Hung Chiang , Hong Kong 10.70 s
7. Francis Manioru , Solomon Islands 11.05 s
8. Teymur Gasimov , Azerbaijan 11.17 s
9. Filipo Muller , Tonga 11.18 s PB

Round 1, Heat 9

1. Deji Aliu , Nigeria 10.39 s Q
2. Nicolas Macrozonaris, Canada 10.40 s Q
3. Gennadiy Chernovol , Kazakhstan 10.43 s Q
4. Souhalia Alamou , Benin 10.48 s
5. Christie van Wyk , Namibia 10.49 s
6. Daniel Bailey , Antigua and Barbuda 10.51 s
7. Gian Nicola Berardi , San Marino 10.76 s
8. Carlos Abaunza , Nicaragua 11.17 s

Round 1, Heat 10

1. Kim Collins, Saint Kitts and Nevis 10.11 s Q
2. Michael Frater , Jamaica 10.20 s Q
3. Nicconnor Alexander , Trinidad and Tobago 10.22 s Q
4. Simone Collio , Italy 10.27 s q
5. Eddy de Lepine , France 10.27 s q SB
6. Xavier James , Bermuda 10.40 s
7. Sebastien Gattuso, Monaco 10.58 s NR
8. Wilfried Bingangoye Gabon 10.76 s PB

Round 2

August 21

Round 2, Heat 1

1. Francis Obikwelu (POR) 9.93 s Q NR
2. Mark Lewis-Francis (GBR) 10.12 s Q SB
3. Dwight Thomas (JAM) 10.12 s Q PB
4. Ronald Pognon (FRA) 10.15 s q
5. Shingo Suetsugu (JPN) 10.19 s
6. Pierre Browne (CAN) 10.21 s
7. Churandy Martina (AHO) 10.24 s
8. Andre Domingos (BRA) 10.34 s

Round 2, Heat 2

1. Shawn Crawford (USA) 9.89 s Q
2. Obadele Thompson (BAR) 10.12 s Q
3. Vicente de Lima (BRA) 10.26 s Q
4. Matic Osovnikar (SLV) 10.26 s
5. Deji Aliu (NIG) 10.26 s
6. Nicolas Macrozonaris (CAN) 10.28 s
7. Gennadiy Chernovol (KAZ) 10.42 s
8. Idrissa Sanou (BUR) 10.43 s

Round 2, Heat 3

1. Justin Gatlin (USA) 9.96 s Q
2. Jason Gardener (GBR) 10.15 s Q SB
3. Uchenna Emedolu (NIG) 10.15 s Q
4. Nobuharu Asahara (JPN) 10.24 s
5. Yeoryios Theodoridis (GRE) 10.36 s
6. Roland Nemeth (HUN) 10.38 s
7. Nicconnor Alexander (TRI) 10.48 s

• Eddy de Lepine (FRA) DNS

Round 2, Heat 4

1. Aziz Zakari (GHA) 10.02 s Q
2. Kim Collins (SKN) 10.05 s Q SB
3. Michael Frater (JAM) 10.11 s Q
4. Frank Fredericks (NAM) 10.17 s
5. Joshua Ross (AUS) 10.22 s PB
6. Alexander Kosenkow (GER) 10.24 s
7. Andrey Yepishin (RUS) 10.29 s
8. Jaysuma Saidy Ndure (GAM) 10.39 s

Round 2, Heat 5

1. Maurice Greene (USA) 9.93 s Q
2. Asafa Powell (JAM) 9.99 s Q
3. Leonard Myles-Mills (GHA) 10.18 s Q SB
4. Lukasz Chyla (POL) 10.23 s
5. Kareem Streete-Thompson (CAY) 10.24 s
6. Simone Collio (ITA) 10.29 s
7. Jarbas Mascarenhas (BRA) 10.30 s
8. Eric Pacome N'Dri (IVO) 10.32 s

Semifinals

August 22

Semifinal 1

1. Shawn Crawford (USA) 10.07 s Q
2. Justin Gatlin (USA) 10.09 s Q
3. Aziz Zakari (GHA) 10.11 s Q
4. Obadele Thompson (BAR) 10.22 s Q
5. Mark Lewis-Francis (GBR) 10.28 s
6. Michael Frater (JAM) 10.29 s
7. Ronald Pognon (FRA) 10.32 s
8. Uchenna Emedolu (NIG) 10.35 s

Semifinal 2

1. Asafa Powell (JAM) 9.95 s Q
2. Francis Obikwelu (POR) 9.97 s Q
3. Maurice Greene (USA) 9.97 s Q
4. Kim Collins (SKN) 10.02 s Q SB
5. Jason Gardener (GBR) 10.12 s SB
6. Leonard Myles-Mills (GHA) 10.22 s
7. Dwight Thomas (JAM) 10.28 s
8. Vicente de Lima (BRA) 10.28 s

Final

August 22

1. Justin Gatlin (USA) 9.85 s PB
2. Francis Obikwelu (POR) 9.86 s AR
3. Maurice Greene (USA) 9.87 s SB
4. Shawn Crawford (USA) 9.89 s
5. Asafa Powell (JAM) 9.94 s
6. Kim Collins (SKN) 10.00 S SB
7. Obadele Thompson (BAR) 10.10 s

• Aziz Zakari (GHA) DNF