Namesakes
Emmy Award Winners:
1 actor
(actor) Dennis Franz 1994; 1996; 1997; 1999 NYPD Blue 
Fictional Characters from Television:
3 characters
Dennis Klinsmann 1994 Heartbreak High
Dennis Finch 1997 Just Shoot Me!
Dennis Reynolds 2005 It's Always Sunny in Philadelphia
Hall-of-Famers:
2 baseball, 2 basketball
(baseball) Dan Brouthers (a.k.a. Dennis) 1945
(baseball) Dennis Eckersley 2004
(basketball) Dennis Johnson 2010
(basketball) Dennis Rodman 2011
Harry Potter Characters:
1 character
Dennis Creevey
Hurricanes and Tropical Storms:
3 hurricanes, 2 storms
Hurricane Dennis 1981
Storm Dennis 1987
Storm Dennis 1993
Hurricane Dennis 1999
Hurricane Dennis 2005
Most Valuable Players:
2 winners
Denny McLain 1968 baseball
Dennis Eckersley 1992 baseball
Nobel Prize Winners:
1 physics
(physics) Dennis Gabor 1971
Notable Activists and Revolutionaries:
1 activist
(activist) Dennis Banks 1937-2017
Notable Actors and Entertainers:
11 actors, 1 comedian
William Gargan (a.k.a. Dennis) 1905-1979
Dennis O'Keefe 1908-1968
Dennis Morgan 1908-1994
Dennis Weaver 1924-2006
Dennis Hopper 1936-2010
Dennis Farina 1944-2013
Dennis Franz 1944-
Dennis Waterman 1948-2022
Dennis Boutsikaris 1952-
Dennis Miller 1953-
Dennis Quaid 1954-
Dennis Haysbert 1954-
Notable Athletes:
2 baseball, 2 basketball, 1 soccer
(baseball) Dan Brouthers (a.k.a. Dennis) 1858-1932
(basketball) Dennis Johnson 1954-2007
(baseball) Dennis Eckersley 1954-
(basketball) Dennis Rodman 1961-
(soccer) Dennis Bergkamp 1969-
Notable Musicians:
1 singer
Dennis Edwards 1943-2018
Notable Scientists and Inventors:
1 engineer, 1 physicist
Dennis Gabor 1900-1979
Dennis Ritchie 1941-2011
Notable Writers:
1 author/poet
D. J. Enright (a.k.a. Dennis) 1920-2002
Olympic Medalists:
2 bronze, 2 silver, 1 bronze/gold/silver
(silver) Dick Hanley (a.k.a. Dennis) 1956 swimming - 4x200 m freestyle relay
(silver) Dave Wilson (a.k.a. Dennis) 1984 swimming - 100 m backstroke
(bronze/gold/silver) Dennis Mitchell 1992; 1996 100 m; 4x100 m relay
(bronze) Dennis Blake 1996 4x400 m relay
(bronze) Dennis van der Geest 2004 judo
Rock and Roll Hall-of-Famers:
4 musicians
Dennis Wilson 1988 The Beach Boys
Dennis Edwards 1989 The Temptations
Denny Doherty 1998 The Mamas & the Papas
Dennis Dunaway 2011 Alice Cooper
Saints:
1 blessed
Blessed Dionysius Fugishima (a.k.a. Dennis) ?-1622
Shakespearian Characters:
1 character
Dennis As You Like It