Namesakes
Emmy Award Winners:
1 actor
(actor) Dennis Franz 1994; 1996; 1997; 1999 NYPD Blue 
Hall-of-Famers:
2 basketball, 1 baseball
(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
Nobel Prize Winners:
1 physics
(physics) Dennis Gabor 1971
Notable Activists and Revolutionaries:
1 activist
(activist) Dennis Banks 1937-2017
Notable Actors and Actresses:
5 actors
Dennis Hopper 1936-2010
Dennis Farina 1944-2013
Dennis Franz 1944-
Dennis Waterman 1948-
Dennis Quaid 1954-
Notable Athletes:
2 basketball, 1 baseball, 1 soccer
(basketball) Dennis Johnson 1954-2007
(baseball) Dennis Eckersley 1954-
(basketball) Dennis Rodman 1961-
(soccer) Dennis Bergkamp 1969-
Notable Hosts and Presenters:
1 radio/television
(radio/television) Dennis Weening 1977-
Notable Musicians:
2 singers
Dennis Edwards 1943-2018
Dennis "Def Rhymz" Bouman 1970- hip hop
Notable Writers:
1 author/poet
D. J. Enright (a.k.a. Dennis) 1920-2002
Olympic Medalists:
3 bronze, 2 silver, 1 bronze/gold/silver
(silver) Richard Hanley (a.k.a. Dennis) 1956 swimming - 4x200 m freestyle relay
(bronze) Earlene Brown (a.k.a. Dennis) 1960 shot put
(silver) David 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
Saints:
2 blessed
Blessed Dionysius Fugishima (a.k.a. Dennis) ?-1622
Blessed Dionisio Pamplona (a.k.a. Dennis) ?-1936
Shakespearian Characters:
1 character
Dennis As You Like It