The fastest athletes under 23 years
| # | Athlete | Nat | Date of Birth | Age | Mark | Venue | Date |
| 1 | David Rudisha | KEN | 17-12-1988 | 21 | 1.41.01 | Rieti | 29-08-2010 |
| 2 | Emmanuel Wanyonyi | KEN | 01-08-2004 | 20 | 1.41.11 | Lausanne | 22-08-2024 |
| 3 | Nijel Amos | BOT | 15-03-1994 | 18 | 1.41.73 | London | 09-08-2012 |
| 4 | Joaquim Cruz | BRA | 12-03-1963 | 21 | 1.41.77 | Köln | 26-08-1984 |
| 5 | Mohamed Attaoui | ESP | 26-09-2001 | 22 | 1.42.04 | Monaco | 12-07-2024 |
| 6 | Abubaker Kaki | SUD | 21-06-1989 | 20 | 1.42.23 | Oslo | 04-06-2010 |
| 7 | Ben Pattison | GBR | 15-12-2001 | 22 | 1.42.27 | Monaco | 12-07-2024 |
| 8 | Cooper Lutkenhaus | USA | 19-12-2008 | 16 | 1.42.27 | Eugene OR | 03-08-2025 |
| 9 | Sebastian Coe | GBR | 29-09-1956 | 22 | 1.42.33 | Oslo | 05-07-1979 |
| 10 | Wilfred Bungei | KEN | 24-07-1980 | 22 | 1.42.34 | Rieti | 08-09-2002 |
| 11 | Donavan Brazier | USA | 15-04-1997 | 22 | 1.42.34 | Doha | 01-10-2019 |
| 12 | Mohammed Aman | ETH | 10-01-1994 | 19 | 1.42.37 | Bruxelles | 06-09-2013 |
| 13 | Yuriy Borzakovskiy | RUS | 12-04-1981 | 20 | 1.42.47 | Bruxelles | 24-08-2001 |
| 14 | Timothy Kitum | KEN | 20-11-1994 | 17 | 1.42.53 | London | 09-08-2012 |
| 15 | Pierre-Ambroise Bosse | FRA | 11-05-1992 | 22 | 1.42.53 | Monaco | 18-07-2014 |
| 16 | Koitatoi Kidali | KEN | 12-02-2003 | 21 | 1.42.66 | Nairobi | 15-06-2024 |
| 17 | Alfred Kirwa Yego | KEN | 28-11-1986 | 22 | 1.42.67 | Rieti | 06-09-2009 |
| 18 | Japheth Kimutai | KEN | 20-12-1978 | 20 | 1.42.69 | Bruxelles | 03-09-1999 |
| 19 | Hezekiél Sepeng | RSA | 30-06-1974 | 22 | 1.42.74 | Atlanta GA | 31-07-1996 |
| 20 | Wilson Kipketer | DEN | 12-12-1972 | 22 | 1.42.87 | Monaco | 25-07-1995 |
| 21 | Alfred Kipketer | KEN | 28-12-1996 | 19 | 1.42.87 | Paris | 27-08-2016 |
| 22 | Handal Roban | VIN | 05-09-2002 | 22 | 1.42.87 | Freeport | 16-08-2025 |
| 23 | Mbulaeni Mulaudzi | RSA | 08-09-1980 | 22 | 1.42.89 | Bruxelles | 05-09-2003 |
| 24 | André Bucher | SUI | 19-10-1976 | 22 | 1.42.92 | Bruxelles | 03-09-1999 |
| 25 | Clayton Murphy | USA | 26-02-1995 | 21 | 1.42.93 | Rio de Janeiro | 15-08-2016 |
| 26 | Boaz Lalang | KEN | 08-02-1989 | 21 | 1.42.95 | Rieti | 29-08-2010 |
| 27 | Ayanleh Souleiman | DJI | 03-12-1992 | 22 | 1.42.97 | Monaco | 17-07-2015 |
| 28 | Jonathan Kitilit | KEN | 24-04-1994 | 22 | 1.43.05 | Paris | 27-08-2016 |
| 29 | Djabir Saïd-Guerni | ALG | 29-03-1977 | 22 | 1.43.09 | Bruxelles | 03-09-1999 |
| 30 | Emmanuel Korir | KEN | 15-06-1995 | 22 | 1.43.10 | Monaco | 21-07-2017 |
| 31 | Youssef Saad Kamel | BRN | 29-03-1983 | 21 | 1.43.11 | Zürich | 06-08-2004 |
| 32 | Wyclife Kinyamal | KEN | 02-07-1997 | 21 | 1.43.12 | London | 22-07-2018 |
| 33 | Abraham Rotich | KEN | 26-06-1993 | 19 | 1.43.13 | Monaco | 20-07-2012 |
| 34 | Asbel Kiprop | KEN | 30-06-1989 | 22 | 1.43.15 | Monaco | 22-07-2011 |
| 35 | Paul Ereng | KEN | 22-08-1967 | 21 | 1.43.16 | Zürich | 16-08-1989 |
| 36 | Benson Koech | KEN | 10-11-1974 | 19 | 1.43.17 | Rieti | 28-08-1994 |
| 37 | Bryce Hoppel | USA | 05-09-1997 | 22 | 1.43.23 | Monaco | 14-08-2020 |
| 38 | Michael Saruni | KEN | 18-06-1995 | 22 | 1.43.25 | Tucson AZ | 28-04-2018 |
| 39 | Marco Arop | CAN | 20-09-1998 | 22 | 1.43.26 | Monaco | 09-07-2021 |
| 40 | Adam Kszczot | POL | 02-09-1989 | 22 | 1.43.30 | Rieti | 10-09-2011 |
| 41 | William Chirchir | KEN | 06-02-1979 | 20 | 1.43.33 | Bruxelles | 03-09-1999 |
| 42 | Boris Berian | USA | 19-12-1992 | 22 | 1.43.34 | Monaco | 17-07-2015 |
| 43 | Leonard Kosencha | KEN | 21-08-1994 | 17 | 1.43.40 | Monaco | 20-07-2012 |
| 44 | Ko Ochiai | JPN | 17-08-2006 | 19 | 1.43.45 | Tokyo | 30-05-2026 |
| 45 | Arthémon Hatungimana | BDI | 21-01-1974 | 22 | 1.43.46 | Zürich | 14-08-1996 |
| 46 | Vebjørn Rodal | NOR | 16-09-1972 | 21 | 1.43.50 | Oslo | 22-07-1994 |
| 47 | Max Burgin | GBR | 20-05-2002 | 22 | 1.43.50 | Paris | 09-08-2024 |
| 48 | Robert Biwott | KEN | 28-01-1996 | 19 | 1.43.56 | Barcelona | 08-07-2015 |
| 49 | Steve Cram | GBR | 14-10-1960 | 22 | 1.43.61 | Oslo | 23-08-1983 |
| 50 | Earl Jones | USA | 17-07-1964 | 22 | 1.43.62 | Zürich | 13-08-1986 |
| 51 | Joseph Mutua | KEN | 10-12-1978 | 22 | 1.43.63 | Monaco | 20-07-2001 |
| 52 | Hobbs Kessler | USA | 15-03-2003 | 21 | 1.43.64 | Eugene OR | 30-06-2024 |
| 53 | Mohammed Al Salhi | KSA | 11-05-1986 | 22 | 1.43.66 | Doha | 08-05-2009 |
| 54 | Amine Laalou | MAR | 13-05-1982 | 22 | 1.43.68 | Zürich | 06-08-2004 |
| 55 | Billy Konchellah | KEN | 20-10-1962 | 22 | 1.43.72 | Koblenz | 28-08-1985 |
| 56 | Abraham Chepkirwok | UGA | 18-11-1988 | 19 | 1.43.72 | Madrid | 05-07-2008 |
| 57 | Jackson Kivuva | KEN | 11-08-1989 | 20 | 1.43.72 | Monaco | 22-07-2010 |
| 58 | Brandon Miller | USA | 30-01-2002 | 22 | 1.43.73 | Eugene OR | 28-06-2024 |
| 59 | Kevin López | ESP | 12-06-1990 | 22 | 1.43.74 | Monaco | 20-07-2012 |
| 60 | Job Kinyor | KEN | 08-05-1990 | 22 | 1.43.76 | Doha | 11-05-2012 |
| 61 | Kipyegon Bett | KEN | 02-01-1998 | 18 | 1.43.76 | Berlin | 03-09-2016 |
| 62 | Edwin Melly | KEN | 06-07-1995 | 17 | 1.43.81 | Rieti | 09-09-2012 |
| 63 | Oliver Dustin | GBR | 29-11-2000 | 20 | 1.43.82 | Nice | 12-06-2021 |
| 64 | Antonio Reina | ESP | 13-06-1981 | 21 | 1.43.83 | Madrid | 21-09-2002 |
| 65 | Olaf Beyer | DDR | 04-08-1957 | 21 | 1.43.84 | Praha | 31-08-1978 |
| 66 | Marcin Lewandowski | POL | 13-06-1987 | 22 | 1.43.84 | Monaco | 28-07-2009 |
| 67 | Francesco Pernici | ITA | 18-02-2003 | 22 | 1.43.84 | Tokyo | 18-09-2025 |
| 68 | Ivo Van Damme | BEL | 21-02-1954 | 22 | 1.43.86 | Montreal | 25-07-1976 |
| 69 | Abdulaziz Mohamed | KSA | 07-01-1991 | 22 | 1.43.86 | Palembang | 26-09-2013 |
| 70 | Donato Sabia | ITA | 11-09-1963 | 20 | 1.43.88 | Firenze | 13-06-1984 |
| 71 | Einars Tupuritis | LAT | 09-12-1973 | 22 | 1.43.90 | Durham NC | 13-07-1996 |
| 72 | Jeremiah Mutai | KEN | 27-12-1992 | 20 | 1.43.9 m | Nairobi | 25-05-2013 |
| 73 | John Marshall | USA | 05-11-1963 | 20 | 1.43.92 | Los Angeles CA | 19-06-1984 |
| 74 | Andrea Benvenuti | ITA | 13-12-1969 | 22 | 1.43.92 | Monaco | 11-08-1992 |
| 75 | Yanis Meziane | FRA | 26-01-2002 | 21 | 1.43.94 | Bruxelles | 08-09-2023 |
| 76 | Brandon McBride | CAN | 15-06-1994 | 22 | 1.43.95 | London | 22-07-2016 |
| 77 | Anthony Chemut | KEN | 17-12-1992 | 19 | 1.43.96 | Nairobi | 23-06-2012 |
| 78 | Jose Parilla | USA | 31-03-1972 | 20 | 1.43.97 | New Orleans LA | 24-06-1992 |
| 79 | Peter Elliott | GBR | 09-10-1962 | 20 | 1.43.98 | Oslo | 23-08-1983 |
| 80 | Bram Som | NED | 20-02-1980 | 21 | 1.43.98 | Monaco | 20-07-2001 |
| 81 | David Mutua | KEN | 20-04-1992 | 19 | 1.43.99 | Monaco | 22-07-2011 |
| 82 | Peyton Craig | AUS | 28-03-2005 | 21 | 1.44.01 | Roma | 04-06-2026 |
| 83 | Belal Mansoor Ali | BRN | 17-10-1985 | 21 | 1.44.02 | Rieti | 09-09-2007 |
| 84 | Cameron Myers | AUS | 09-06-2006 | 19 | 1.44.05 | Karlsruhe | 30-05-2026 |
| 85 | Jean-Patrick Nduwimana | BDI | 09-05-1978 | 22 | 1.44.06 | Bruxelles | 25-08-2000 |
| 86 | Abderrahman El Assal | MAR | 10-06-2005 | 20 | 1.44.07 | Fès | 15-06-2025 |
| 87 | Ibrahim Abass Chuot | QAT | 05-07-2004 | 20 | 1.44.08 | Doha | 16-05-2025 |
| 88 | Steve Ovett | GBR | 09-10-1955 | 22 | 1.44.09 | Praha | 31-08-1978 |
| 89 | Vincent Malakwen | KEN | 19-07-1974 | 21 | 1.44.1 m | Nairobi | 03-05-1996 |
| 90 | Henry Jonas | GBR | 08-06-2005 | 20 | 1.44.10 | Bergen | 18-07-2025 |
| 91 | Lee Jin-Il | KOR | 12-01-1973 | 21 | 1.44.14 | Seoul | 17-06-1994 |
| 92 | René Herms | GER | 17-07-1982 | 22 | 1.44.14 | München | 08-08-2004 |
| 93 | Raynier Galvez | USA | 02-03-2006 | 20 | 1.44.14 | Fayetteville AR | 24-04-2026 |
| 94 | Luke Boyes | AUS | 05-11-2003 | 22 | 1.44.16 | Shanghai | 16-05-2026 |
| 95 | Alexander Stepanov | GER | 30-09-2004 | 20 | 1.44.17 | Pfungstadt | 14-06-2025 |
| 96 | Adrián Ben | ESP | 04-08-1998 | 22 | 1.44.18 | Stockholm | 04-07-2021 |
| 97 | Niels Laros | NED | 17-04-2005 | 20 | 1.44.19 | Bergen | 18-07-2025 |
| 98 | Juma N'Diwa | KEN | 28-11-1960 | 22 | 1.44.20 | München | 26-07-1983 |
| 99 | Rob Druppers | NED | 29-04-1962 | 21 | 1.44.20 | Helsinki | 09-08-1983 |
| 100 | Joseph Deng | AUS | 07-07-1998 | 20 | 1.44.21 | Monaco | 20-07-2018 |
| 101 | Alex Kipngetich | KEN | 17-08-2000 | 22 | 1.44.21 | Nairobi | 08-07-2023 |
| 102 | Nils Schumann | GER | 20-05-1978 | 22 | 1.44.22 | Sydney | 25-09-2000 |
| 103 | Edmund Du Plessis | RSA | 05-04-2002 | 22 | 1.44.22 | Dublin | 12-07-2024 |
| 104 | Maciej Wyderka | POL | 29-07-2002 | 22 | 1.44.23 | Poznan | 05-07-2025 |
| 105 | Ismael Kombich | KEN | 16-10-1985 | 20 | 1.44.24 | Lausanne | 11-07-2006 |
| 106 | Wassili Matveyev | USR | 04-02-1962 | 22 | 1.44.25 | Kiev | 22-06-1984 |
| 107 | Ilham Tanui Özbilen | TUR | 05-03-1990 | 21 | 1.44.25 | Ninove | 06-08-2011 |
| 108 | Will Sumner | USA | 22-10-2003 | 19 | 1.44.26 | Austin TX | 09-06-2023 |
| 109 | Majid Saeed Sultan | QAT | 03-11-1986 | 18 | 1.44.27 | Incheon | 04-09-2005 |
| 110 | Bob Abdelrahim | AUS | 16-03-2006 | 19 | 1.44.27 | Perth | 14-02-2026 |
| 111 | Mark Everett | USA | 02-09-1968 | 22 | 1.44.28 | New York NY | 15-06-1991 |
| 112 | André Olivier | RSA | 29-12-1989 | 22 | 1.44.29 | Monaco | 20-07-2012 |
| 113 | Jim Ryun | USA | 29-04-1947 | 19 | 1.44.3 y | Terre Haute IN | 10-06-1966 |
| 114 | Dave Wottle | USA | 07-08-1950 | 21 | 1.44.3 m | Eugene OR | 01-07-1972 |
| 115 | José Luiz Barbosa | BRA | 21-05-1961 | 22 | 1.44.3 m | São Paulo | 26-06-1983 |
| 116 | Ethan Hussey | GBR | 05-03-2003 | 22 | 1.44.30 | London | 19-07-2025 |
| 117 | Rafith Rodriguez | COL | 01-06-1989 | 21 | 1.44.31 | Belém | 15-05-2011 |
| 118 | Abubaker Haydar Abdalla | QAT | 28-08-1996 | 22 | 1.44.33 | Doha | 22-04-2019 |
| 119 | Mohamed Ali Gouaned | ALG | 05-07-2002 | 22 | 1.44.33 | Tomblaine | 04-07-2025 |
| 120 | Nicholas Wachira | KEN | 19-11-1982 | 20 | 1.44.34 | Nairobi | 26-07-2003 |
| 121 | Justin Davies | GBR | 06-02-2003 | 22 | 1.44.35 | Belfast | 10-05-2025 |
| 122 | Ermiyas Girma | ETH | 20-01-2005 | 17 | 1.44.36 | Lokeren | 22-05-2022 |
| 123 | Daniel Williams | AUS | 03-08-2007 | 18 | 1.44.37 | Adelaide | 14-03-2026 |
| 124 | Haithem Chenitef | ALG | 30-01-2004 | 21 | 1.44.38 | Toulouse | 29-05-2025 |
| 125 | David Mack | USA | 30-05-1961 | 22 | 1.44.39 | Koblenz | 31-08-1983 |
| 126 | Sam Koskei | KEN | 14-05-1961 | 22 | 1.44.40 | Villanova PA | 12-06-1983 |
| 127 | Andrea Longo | ITA | 26-06-1975 | 21 | 1.44.40 | Roma | 05-06-1997 |
| 128 | Alex Rowe | AUS | 08-07-1992 | 22 | 1.44.40 | Monaco | 18-07-2014 |
| 129 | Paul Anselmini | FRA | 02-08-2003 | 21 | 1.44.40 | Décines | 05-07-2025 |
| 130 | Werner Botha | RSA | 31-01-1978 | 22 | 1.44.41 | Heusden | 05-08-2000 |
| 131 | Isaiah Harris | USA | 18-10-1996 | 21 | 1.44.42 | Paris | 30-06-2018 |
| 132 | Colin Sahlman | USA | 28-10-2003 | 22 | 1.44.42 | Azusa CA | 17-04-2026 |
| 133 | Tracy Baskin | USA | 03-11-1965 | 22 | 1.44.43 | Zürich | 17-08-1988 |
| 134 | Noah Kibet | KEN | 12-04-2004 | 22 | 1.44.44 | Nairobi | 24-04-2026 |
| 135 | Sam Whitmarsh | USA | 18-10-2002 | 21 | 1.44.46 | Baton Rouge LA | 30-03-2024 |
| 136 | Otukile Lekote | BOT | 19-10-1978 | 22 | 1.44.47 | Montreal | 10-07-2001 |
| 137 | Joseph Tengelei | KEN | 08-12-1970 | 22 | 1.44.48 | Keuruu | 26-06-1993 |
| 138 | Jakub Dudycha | CZE | 05-09-2005 | 19 | 1.44.48 | Ostrava | 24-06-2025 |
| 139 | Noah Ngeny | KEN | 02-11-1978 | 21 | 1.44.49 | Oslo | 28-07-2000 |
| 140 | Elvin Josué Canales | ESP | 05-09-2001 | 22 | 1.44.49 | Guadalajara | 23-06-2024 |
| 141 | Yohannes Tefera | ETH | 28-03-2004 | 21 | 1.44.49 | Tomblaine | 04-07-2025 |
| 142 | Matti Erickson | CAN | 11-03-2003 | 22 | 1.44.49 | Eagle Rock CA | 12-07-2025 |