Women's 50m Breaststroke
· Lilly King (USA) became the second woman to win the 50m and 100m breaststroke at the same world championships after Luo Xuejuan (CHN, 2001 and 2003).
· King won both of those world titles in world record times (29.40 in 50m). She ousted the previous top time of 29.48, clocked by Ruta Meilutyte (LTU) in 2013.
· King became the second US swimmer to break the women's 50m breaststroke world record, after Jessica Hardy (USA) achieved this twice in 2009.
· United States have now won this event three times at the world championships, most of any nation. The previous two both went to Hardy (2007 and 2011).
· Silver medallist Yuliya Efimova (RUS) claimed a fifth successive medal in this event at the world championships. She won the world title in 2009 and 2013, while claiming silver in 2011 and bronze in 2015.
· Efimova's five medals are a new record in this event at the world championships which she previously shared with Hardy (G2-S1-B1).
· Katie Meili (USA) took bronze, her second medal here in Budapest. She claimed silver behind King at the double distance.
Men's 400m Individual Medley
· Chase Kalisz (USA) became the fifth man to win the 200m and 400m individual medley at a single world championships, after Ryan Lochte (USA), Michael Phelps (USA), Tamás Darnyi (HUN) and András Hargitay (HUN).
· Kalisz (USA) gave USA their 250th gold medal at the FINA World Aquatics Championships.
· Silver medallist David Verraszto (HUN) also finished second two years ago in Kazan. It was the 10th medal for Hungary in this event, second most behind USA (19 medals).
· Bronze medallist Dalya Seto (JPN) claimed his third medal in this event at the world championships, after his wins in 2013 and 2015. He equalled Ryan Lochte (USA), András Hargitay (HUN), László Cseh (HUN) and Kalisz for a record most medals in this event.
Women's 50m Freestyle
· Sarah Sjöström (SWE) won her first ever freestyle gold medal at world championships.
· She is the third woman with a world title in both 50m freestyle and 50m butterfly, after Inge de Bruijn (NED) and Therese Alshammar (SWE).
· Sjöström became the second woman to manage the double at a single world championships, after De Bruijn in 2001 and 2003.
· Silver medallist Ranomi Kromowidjojo (NED) claimed her fourth medal in the 50m freestyle, after gold in 2013 and silver in 2011 and 2015. She joined Therese Alshammar (SWE, G1-S3-B0) and Marleen Veldhuis (NED, G0-S1-B3) as the most decorated swimmers in this event.
· In each of the last nine editions of the world championships there has been a Dutch swimmer on the podium in the women's 50m freestyle, grabbing 10 medals in total in this span (G3-S4-B3).
· Kromowidjojo claimed her 16th medal at the world championships, equalling Missy Franklin (USA) in second place all-time among women, behind only Natalie Coughlin (USA, 19).
· Simone Manuel (USA) took bronze. This is the fourth total women's 50m freestyle medal for United States, after Amy Van Dyken's (USA) gold medal in 1998, Van Dyken's bronze in 1994 and Leigh Fetter's (USA) silver in 1991.
Men's 50m Backstroke
· Camille Lacourt (FRA) won his fifth world title in any event, surpassing Jérémy Stavius (FRA) and Florent Manaudou (FRA) for a record most among French swimmers (men and women).
· Lacourt won the first world title for France at these world championships. France have now won world titles at each of the last four world championships.
· Silver medallist Junya Koga (JPN) grabbed his third world championships medal, and his first in eight years as he claimed gold (100m backstroke) and silver (50m backstroke) in 2009.
· Bronze medallist Matt Grevers (USA) claimed his sixth medal in any backstroke event at the world championships, equalling Ryan Lochte (USA) and Emily Seebohm (AUS), in second place behind Aaron Peirsel (USA, 8).
Women's 400m Individual Medley
· Katinka Hosszú (HUN) claimed her fourth 400m individual medley world title and her seventh gold medal in 200m/400m individual medley combined, a record among men and women as Ryan Lochte (USA) has six titles.
· Hosszú claimed her 13th medal in individual events at the world championships, equalling her compatriot László Cseh (HUN) for fourth-most among men and women. Only Michael Phelps (USA, 20), Ryan Lochte (USA, 16) and Grant Hackett (AUS, 14) have more.
· Hosszú has won the last 20 400m individual medley finals she participated in at major level (OG, WCh, ECh, World Cup, Mare Nostrum).
· After taking gold in women's 200m butterfly and silver in women's 1500m freestyle earlier this week, Mireia Belmonte (ESP) added a silver in women's 4x100m individual medley. In 2013, she also took silver behind Katinka Hosszú (HUN) in this event.
· Sydney Pickrem (CAN) took bronze to become the second medallist from Canada in this event. The first was Emily Overholt (CAN), who took bronze in Kazan two years ago.
Men's 1500m Freestyle
· Gregorio Paltrinieri (ITA) claimed his fifth medal at the world championships, equalling the men's record for Italians, set by Massimiliano Rosolino (ITA).
· Paltrinieri gave Italy their third gold medal at these world championships, equalling Italy's record at a single edition of the world championships (3 in 2009).
· Paltrinieri bagged Italy's sixth medal at these swimming world championships, equalling the country's record set in 1991 and equalled in 2001 and 2007.
· For the fifth successive world championships in a post-Olympic year, the men's 1500m freestyle was won by the reigning Olympic champion: Grant Hackett (AUS) in 2001 and 2005, Oussama Mellouli (TUN) in 2009, Sun Yang (CHN) in 2013 and Paltrinieri in 2017.
· Mykhailo Romanchuk (UKR) claimed his first medal at the world championships. It is Ukraine's second medal at these world championships, after Andrii Govorov claimed bronze in the men's 50m butterfly.
· Bronze medallist Mack Horton (AUS) claimed his first medal in this event. He finished third in the 800m freestyle in 2015 and second in the 400m freestyle one week ago.
· Horton became the first Australian other than Hackett to win a medal in this event, since Daniel Kowalski's (AUS) bronze medal in 1998.
Women's 4x100m Medley Relay
· United States won a sixth gold medal in this event at the world championships. They also claimed nine silver medals.
· Only in 2009 (10th) and 2015 (4th), the Americans have failed to reach the podium.
· USA won this world title as the reigning Olympic champions for the third time, after doing so in 2013 and in 1998.
· Mallory Comerford (USA) and Simone Manuel (USA) joined Katie Ledecky (USA) on five gold medals in Budapest. Only one female swimmer claimed more than five world titles in a single year, six by Missy Franklin (USA) in Barcelona in 2013.
· Russia took silver, their best result in this event at the world championships. In 1994 and 2013, they bagged the bronze medal.
· Australia finished in third place, which means Emily Seebohm (AUS, G1-S2-B2) equalled Leisel Jones (AUS, G3-S0-B2) and Natalie Coughlin (USA, G1-S4-B0) on a record five medals in this event.
· With her 14th total medal at the world championships, Seebohm advanced in joint-third position among Australian swimmers. She equalled Jones and now only trails Libby Trickett (AUS, 15) and Grant Hackett (AUS, 19).
· Emma McKeon (AUS) claimed her sixth medal in Budapest (G0-S4-B2), a record for an Australian swimmer at a single edition of the world championships.
· McKeon and Manuel equalled Ledecky on a women's record six medals at the 2017 world championships.
· This was Australia's 200th medal in swimming at world championships.
Men's 4x100m Medley Relay
· United States won a medal in this event for the 14th time (G13-S1-B0) of the 17 times it was contested at the world championships. They only missed out in 2001, 2007 and 2013.
· USA extended their world championships medal count to 38 in swimming with this event, a new record by one country at a single edition. USA set the record of 36 in 1978 and equalled that in 2007.
· Caeleb Dressel (USA) equalled Michael Phelps (USA) on a record seven gold medals at a single world championships. Phelps achieved this feat 10 years ago in 2007. Dressel is almost a year younger now (20-348) than Phelps was in 2007 (21-275).
· Nathan Adrian (USA) won his eighth relay world title, surpassing Missy Franklin (USA) and equalling Ryan Lochte (USA) for second most behind Phelps (11).
· Matt Grevers (USA) has won seven world championships medals after at the age of 30 or older (all events combined), two more than any other swimmer as Jenny Thomson (USA) has five.
· Silver medallist Great Britain took their third medal in this event at the world championships, after finishing third in 1975 and 1978.
· Adam Peaty (GBR) and James Guy (GBR) grabbed a sixth medal at world championships, ousting David Wilkie (GBR, 5) and Liam Tancock (GBR, 5) for most among Britons, male or female.
· Russia won their first medal in this event in 10 years (bronze in 2007). It is their 10th medal at these swimming world championships, second-most for them at a single edition (excluding Soviet Union), after their 11 in 1994.