There is a total of 31390 clues beginning with on
- One of the world's great oil ports
- One of the world's great shrines
- One of the world's great writers
- One of the world's greatest mining centers
- One of the world's hottest chili peppers (over 900 times hotter than Tabasco sauce), aka "ghost pepper"
- One of the world's largest islands
- One of the world's last remaining People's Democratic Republics
- One of the world's longest rivers
- One of the world's most popular names
- One of the world's most radioactive waterways due to contamination from the Sellafield Nuclear Plant
- One of the world's oldest capitals
- One of the world's oldest countries
- One of the world's religions
- One of the world's trillion-dollar economies
- One of the worlds
- One of the worlds in "The War of the Worlds"
- One of the Wright brothers
- One of the Wright brothers, for short
- One of the Wrights
- One of the Wu-Tang Clan members, for short
- One of the Wu-Tang Clan rappers, for short
- One of the WWII Allies
- One of the Wyeths
- One of the Wylies
- One of the Wynns
- One of the Wynns
- One of the X's in X-X-X
- One of the X's in XXX
- One of the X-Men
- One of the Yales
- One of the Yalies
- One of the Yalta threesome
- One of the Yankees' M&M sluggers
- One of the Yokums
- One of the Yokums
- One of the Yorks
- One of the Youngers
- One of the Yugoslavs
- One of the Yum! brands
- One of the zany Ritz Brothers
- One of the Zappas
- One of the Zodiac's 12
- One of the zones
- One of the Zones
- One of the zones: Abbr
- One of the zoo's attractions
- One of the “Gilligan’s Island” castaways
- One of their favorite games is curling
- One of them does?
- One of them has an Interstate!
- One of them is hidden in 17-, 25-, 30- and 45-Across
- One of them won in 1804
- One of them won in Roman myth
- One of them won in the bible
- One of them, maybe
- One of them?
- One of these begins 21, 34, 44, and 58A
- One of these can be found reading counterclockwise somewhere in each concentric ring
- One of these days
- One of these is a lot
- One of these lurks in 20-, 30-, 41- and 51-Across
- One of these was a pal of 18 Across
- One of thirteen
- One of thirteen cards
- One of thirteen
- One of this puzzle's 144
- One of this puzzle's 78
- One of Thomas Jefferson's pursuits
- One of Thor Heyerdahl's boats
- One of those
- One of those "SNL" parody ads, say?
- One of those "with their eyes all aglow" in a seasonal song
- One of those brief days
- One of those girls
- One of those Judds
- One of those MacArthur called "my best soldiers"
- One of those people who play with their food?
- One of those Spice Islands
- One of those things
- One of those things?
- One of those who mind their manors
- One of those?
- One of thousands in a Rose Bowl float
- One of thousands of small planets
- One of three
- One of three 1994 Peace Nobelists
- One of three articles
- One of three articles in English
- One of three at Giza
- One of three at the base of a Steinway
- One of three at the start of "the Scottish play"
- One of three at the start of a Pac-Man game
- One of three B's
- One of three B's
- One of three bears
- One of three bears in a fairy tale
- One of three Belgian kings
- One of three biblical brothers
- One of three biblical gifts
- One of three billion