15-letter words starting with O

Are you looking for 15-letter words that start with O that you can play in Scrabble? The list below contains 257 words that are fifteen letters long, starting with O.

You can also find words of different lengths that start in O by using the links below. We have words in our dictionary ranging from 2-15 letters in length.

Find more words by length

2 3 4 5 6 7 8 9 10 11 12 13 14 15
Word Points US Intl.
1 OBJECTIFICATION 31 ✅ ✅
2 OBJECTIVENESSES 29 ✅ ✅
3 OBLIVIOUSNESSES 20 ✅ ✅
4 OBNOXIOUSNESSES 24 ✅ ✅
5 OBSERVABILITIES 22 ✅ ✅
6 OBSERVATIONALLY 23 ✅ ✅
7 OBSESSIVENESSES 20 ✅ ✅
8 OBSTINATENESSES 17 ✅ ✅
9 OBSTRUCTIONALLY 22 ✅ ❌
10 OBSTRUCTIONISMS 21 ✅ ✅
11 OBSTRUCTIONISTS 19 ✅ ✅
12 OBSTRUCTIVENESS 22 ✅ ✅
13 OBTAINABILITIES 19 ✅ ✅
14 OBTRUSIVENESSES 20 ✅ ✅
15 OCCASIONALITIES 19 ✅ ❌
16 OCCIDENTALISING 21 ✅ ❌
17 OCCIDENTALIZING 30 ✅ ✅
18 OCCLUSIVENESSES 22 ✅ ❌
19 OCEANOGRAPHICAL 25 ✅ ✅
20 OCHLOCRATICALLY 27 ✅ ❌
21 OCTOCENTENARIES 19 ✅ ❌
22 ODONTORHYNCHOUS 27 ✅ ❌
23 ODONTOSTOMATOUS 18 ✅ ❌
24 ODORIFEROUSNESS 19 ✅ ✅
25 OESOPHAGOSCOPES 25 ✅ ❌
26 OESTROGENICALLY 21 ✅ ❌
27 OFFENSIVENESSES 24 ✅ ✅
28 OFFHANDEDNESSES 26 ✅ ✅
29 OFFICIOUSNESSES 23 ✅ ✅
30 OLIGOCYTHAEMIAS 26 ✅ ❌
31 OLIGODENDROCYTE 23 ✅ ✅
32 OLIGODENDROGLIA 19 ✅ ✅
33 OLIGOMERISATION 18 ✅ ❌
34 OLIGOMERIZATION 27 ✅ ✅
35 OLIGONUCLEOTIDE 19 ✅ ✅
36 OLIGOSACCHARIDE 24 ✅ ✅
37 OMNIBENEVOLENCE 24 ✅ ❌
38 OMNICOMPETENCES 25 ✅ ✅
39 OMNIDIRECTIONAL 20 ✅ ✅
40 OMNIFARIOUSNESS 20 ✅ ❌
41 OMNISEXUALITIES 24 ❌ ✅
42 OMOPLATOSCOPIES 23 ✅ ❌
43 ONCOGENETICISTS 20 ✅ ❌
44 ONEIROCRITICISM 21 ✅ ❌
45 ONTOGENETICALLY 21 ✅ ✅
46 ONYCHOCRYPTOSES 30 ✅ ❌
47 ONYCHOCRYPTOSIS 30 ✅ ❌
48 OOPHORECTOMISED 25 ✅ ❌
49 OOPHORECTOMISES 24 ✅ ❌
50 OOPHORECTOMIZED 34 ✅ ❌
51 OOPHORECTOMIZES 33 ✅ ❌
52 OPENHEARTEDNESS 21 ✅ ✅
53 OPENMOUTHEDNESS 23 ✅ ✅
54 OPERATIONALISMS 19 ✅ ✅
55 OPERATIONALISTS 17 ✅ ✅
56 OPERATIVENESSES 20 ✅ ✅
57 OPHTHALMOLOGIES 26 ✅ ✅
58 OPHTHALMOLOGIST 26 ✅ ✅
59 OPHTHALMOMETERS 27 ✅ ❌
60 OPHTHALMOPHOBIA 32 ✅ ❌
61 OPHTHALMOPLEGIA 28 ✅ ❌
62 OPHTHALMOSCOPES 29 ✅ ✅
63 OPHTHALMOSCOPIC 31 ✅ ✅
64 OPINIONATEDNESS 18 ✅ ✅
65 OPISTHOGNATHISM 26 ✅ ❌
66 OPISTHOGNATHOUS 24 ✅ ❌
67 OPISTHOGRAPHIES 26 ✅ ❌
68 OPPORTUNENESSES 19 ✅ ✅
69 OPPROBRIOUSNESS 21 ✅ ✅
70 OPSONIFICATIONS 22 ✅ ❌
71 OPTIMALISATIONS 19 ✅ ❌
72 OPTIMALIZATIONS 28 ✅ ❌
73 OPTOELECTRONICS 21 ✅ ✅
74 ORACULOUSNESSES 17 ✅ ❌
75 ORCHESOGRAPHIES 26 ✅ ❌
76 ORCHESTRATIONAL 20 ✅ ✅
77 OREOGRAPHICALLY 26 ❌ ❌
78 ORGANOCHLORINES 21 ✅ ✅
79 ORGANOGRAPHICAL 24 ✅ ❌
80 ORGANOGRAPHISTS 22 ✅ ❌
81 ORGANOMERCURIAL 20 ✅ ✅
82 ORGANOMETALLICS 20 ✅ ✅
83 ORGANOPHOSPHATE 26 ✅ ✅
84 ORGANOTHERAPIES 21 ✅ ❌
85 ORIENTALIZATION 24 ❌ ✅
86 ORIENTATIONALLY 18 ✅ ✅
87 ORNITHODELPHIAN 24 ✅ ❌
88 ORNITHODELPHOUS 24 ✅ ❌
89 ORNITHORHYNCHUS 29 ✅ ❌
90 ORTHOCHROMATISM 27 ✅ ❌
91 ORTHODONTICALLY 24 ✅ ✅
92 ORTHOGONALISING 20 ✅ ❌
93 ORTHOGONALITIES 19 ✅ ✅
94 ORTHOGONALIZING 29 ✅ ✅
95 ORTHOPAEDICALLY 26 ❌ ❌
96 ORTHOPHOSPHATES 28 ✅ ✅
97 ORTHOPHOSPHORIC 30 ✅ ❌
98 ORTHOPSYCHIATRY 31 ✅ ✅
99 OSCILLOGRAPHIES 23 ✅ ✅
100 OSMOREGULATIONS 18 ✅ ✅
101 OSTENSIBILITIES 17 ✅ ❌
102 OSTEOARTHRITICS 20 ✅ ❌
103 OSTEOMYELITIDES 21 ❌ ✅
104 OSTEOMYELITISES 20 ✅ ✅
105 OSTEOPATHICALLY 25 ✅ ✅
106 OSTREICULTURIST 17 ✅ ❌
107 OTHERWORLDLIEST 22 ❌ ❌
108 OUTDOORSMANSHIP 23 ✅ ✅
109 OUTMANIPULATING 20 ✅ ✅
110 OUTSPOKENNESSES 21 ✅ ✅
111 OVERABSTRACTING 23 ❌ ❌
112 OVERABSTRACTION 22 ❌ ✅
113 OVERACCENTUATED 23 ✅ ✅
114 OVERACCENTUATES 22 ✅ ✅
115 OVERACHIEVEMENT 28 ✅ ✅
116 OVERADJUSTMENTS 28 ✅ ✅
117 OVERADVERTISING 23 ✅ ✅
118 OVERADVERTIZING 32 ❌ ❌
119 OVERALERTNESSES 18 ❌ ✅
120 OVERAMBITIOUSLY 25 ❌ ✅
121 OVERAPPLICATION 24 ✅ ✅
122 OVERARTICULATED 21 ✅ ✅
123 OVERARTICULATES 20 ✅ ✅
124 OVERASSESSMENTS 20 ✅ ✅
125 OVERBEARINGNESS 21 ✅ ❌
126 OVERCAPITALISED 23 ✅ ❌
127 OVERCAPITALISES 22 ✅ ❌
128 OVERCAPITALIZED 32 ✅ ✅
129 OVERCAPITALIZES 31 ✅ ✅
130 OVERCENTRALISED 21 ✅ ❌
131 OVERCENTRALISES 20 ✅ ❌
132 OVERCENTRALIZED 30 ✅ ✅
133 OVERCENTRALIZES 29 ✅ ✅
134 OVERCLASSIFYING 27 ✅ ✅
135 OVERCOMMITMENTS 26 ✅ ✅
136 OVERCOMMUNICATE 26 ✅ ✅
137 OVERCOMPENSATED 25 ✅ ✅
138 OVERCOMPENSATES 24 ✅ ✅
139 OVERCOMPLIANCES 26 ✅ ✅
140 OVERCOMPLICATED 27 ✅ ✅
141 OVERCOMPLICATES 26 ✅ ✅
142 OVERCOMPRESSING 25 ✅ ✅
143 OVERCONFIDENCES 26 ✅ ✅
144 OVERCONFIDENTLY 27 ✅ ✅
145 OVERCONSTRUCTED 23 ✅ ✅
146 OVERCONSUMPTION 24 ✅ ✅
147 OVERCONTROLLING 21 ✅ ✅
148 OVERCORRECTIONS 22 ✅ ✅
149 OVERCREDULITIES 21 ✅ ❌
150 OVERCULTIVATION 23 ✅ ✅
151 OVERDECORATIONS 21 ✅ ✅
152 OVERDEPENDENCES 24 ✅ ✅
153 OVERDEVELOPMENT 26 ✅ ✅
154 OVERDISCOUNTING 22 ✅ ✅
155 OVERDIVERSIFIED 26 ❌ ❌
156 OVERDIVERSITIES 22 ✅ ✅
157 OVERDOCUMENTING 24 ✅ ✅
158 OVERDRAMATISING 22 ✅ ❌
159 OVERDRAMATIZING 31 ✅ ✅
160 OVEREAGERNESSES 19 ✅ ✅
161 OVEREARNESTNESS 18 ❌ ✅
162 OVERELABORATING 21 ✅ ✅
163 OVERELABORATION 20 ✅ ✅
164 OVEREMBELLISHED 26 ✅ ✅
165 OVEREMBELLISHES 25 ✅ ✅
166 OVEREMOTIONALLY 23 ❌ ✅
167 OVEREMPHASISING 26 ✅ ❌
168 OVEREMPHASIZING 35 ✅ ✅
169 OVEREMPLOYMENTS 27 ❌ ❌
170 OVERENCOURAGING 22 ✅ ✅
171 OVERENGINEERING 20 ✅ ✅
172 OVERENTERTAINED 19 ✅ ✅
173 OVERENTHUSIASMS 23 ✅ ✅
174 OVERESTIMATIONS 20 ✅ ✅
175 OVEREVALUATIONS 21 ✅ ✅
176 OVEREXAGGERATED 28 ✅ ✅
177 OVEREXAGGERATES 27 ✅ ✅
178 OVEREXCITEMENTS 29 ❌ ✅
179 OVEREXPECTATION 29 ✅ ✅
180 OVEREXTRACTIONS 27 ✅ ✅
181 OVEREXTRAPOLATE 27 ❌ ✅
182 OVEREXTRAVAGANT 29 ✅ ✅
183 OVEREXUBERANTLY 30 ❌ ✅
184 OVERFAMILIARITY 26 ✅ ✅
185 OVERFERTILISING 22 ✅ ❌
186 OVERFERTILIZING 31 ✅ ✅
187 OVERFLOURISHING 25 ✅ ❌
188 OVERFORWARDNESS 25 ✅ ❌
189 OVERFULFILLMENT 26 ❌ ✅
190 OVERGENERALISED 20 ✅ ❌
191 OVERGENERALISES 19 ✅ ❌
192 OVERGENERALIZED 29 ✅ ✅
193 OVERGENERALIZES 28 ✅ ✅
194 OVERGLAMORISING 22 ✅ ❌
195 OVERGLAMORIZING 31 ✅ ✅
196 OVERGLAMOURIZED 31 ❌ ✅
197 OVERGLAMOURIZES 30 ❌ ✅
198 OVERHASTINESSES 21 ✅ ❌
199 OVERHOMOGENISED 25 ✅ ❌
200 OVERHOMOGENISES 24 ✅ ❌
201 OVERHOMOGENIZED 34 ✅ ✅
202 OVERHOMOGENIZES 33 ✅ ✅
203 OVERIDENTIFYING 26 ✅ ✅
204 OVERIMAGINATIVE 24 ✅ ✅
205 OVERINDULGENCES 22 ✅ ✅
206 OVERINGENUITIES 19 ✅ ✅
207 OVERINTENSITIES 18 ✅ ✅
208 OVERINTERPRETED 21 ❌ ✅
209 OVERINVESTMENTS 23 ✅ ✅
210 OVERLENGTHENING 23 ✅ ✅
211 OVERMANAGEMENTS 23 ❌ ✅
212 OVERMEDICATIONS 23 ✅ ✅
213 OVERMULTIPLYING 26 ✅ ❌
214 OVERMULTITUDING 22 ✅ ❌
215 OVERNOURISHMENT 23 ❌ ✅
216 OVEROPINIONATED 21 ✅ ✅
217 OVERORCHESTRATE 23 ✅ ✅
218 OVERORNAMENTING 21 ✅ ✅
219 OVERPERSUASIONS 20 ✅ ✅
220 OVERPESSIMISTIC 24 ❌ ❌
221 OVERPOPULATIONS 22 ✅ ✅
222 OVERPREDICTIONS 23 ❌ ✅
223 OVERPREPARATION 22 ✅ ❌
224 OVERPRESCRIBING 25 ✅ ✅
225 OVERPRODUCTIONS 23 ✅ ✅
226 OVERPROGRAMMING 26 ✅ ✅
227 OVERPROPORTIONS 22 ✅ ✅
228 OVERPROTECTIONS 22 ✅ ✅
229 OVERREFINEMENTS 23 ✅ ✅
230 OVERREGULATIONS 19 ✅ ✅
231 OVERREPRESENTED 21 ✅ ✅
232 OVERSATURATIONS 18 ✅ ✅
233 OVERSENSITIVITY 24 ✅ ✅
234 OVERSIMPLIFYING 29 ✅ ✅
235 OVERSPECIALISED 23 ✅ ❌
236 OVERSPECIALISES 22 ✅ ❌
237 OVERSPECIALIZED 32 ✅ ✅
238 OVERSPECIALIZES 31 ✅ ✅
239 OVERSPECULATING 23 ✅ ✅
240 OVERSPECULATION 22 ✅ ✅
241 OVERSTABILITIES 20 ✅ ✅
242 OVERSTIMULATING 21 ✅ ✅
243 OVERSTIMULATION 20 ✅ ✅
244 OVERSTRUCTURING 21 ❌ ✅
245 OVERSUBSCRIBING 25 ✅ ✅
246 OVERSWEETNESSES 21 ✅ ✅
247 OVERUTILISATION 18 ✅ ❌
248 OVERUTILIZATION 27 ✅ ✅
249 OVERWEENINGNESS 22 ✅ ❌
250 OVERWITHHOLDING 29 ✅ ✅
251 OVERZEALOUSNESS 27 ✅ ✅
252 OVOVIVIPARITIES 26 ✅ ❌
253 OVOVIVIPAROUSLY 29 ✅ ✅
254 OXIDOREDUCTASES 26 ✅ ✅
255 OXYHAEMOGLOBINS 33 ✅ ❌
256 OXYPHENBUTAZONE 41 ✅ ✅
257 OXYTETRACYCLINE 32 ✅ ✅

Scrabble score table

The table below covers how many points each letter will give you when playing a game of Scrabble. The most common letters are worth one point, and the rarest letters are worth 8-10 points.

You can use our Scrabble tools to help you learn and remember words which contain the rare letters to make sure you get the highest score possible!

Score Letters
1 AEIOULNRST
2 DG
3 BCMP
4 FHVWY
5 K
8 JX
10 QZ

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  • "15-letter words starting with O". WordSquared.com. Accessed on December 5, 2023. https://wordsquared.com/scrabble/fifteen-letter-words-starting-with-o/.

  • "15-letter words starting with O". WordSquared.com, https://wordsquared.com/scrabble/fifteen-letter-words-starting-with-o/. Accessed 5 December, 2023

  • 15-letter words starting with O. WordSquared.com. Retrieved from https://wordsquared.com/scrabble/fifteen-letter-words-starting-with-o/.