Essential oils are volatile and liquid aroma compounds from natural sources, usually plants. Essential oils are not oils in a strict sense, but often share with oils a poor solubility in water. Essential oils often have an odor and are therefore used in food flavoring and perfumery. Essential oils are usually prepared by fragrance extraction techniques such as distillation (including steam distillation), cold pressing, or extraction (maceration). Essential oils are distinguished from aroma oils (essential oils and aroma compounds in an oily solvent), infusions in a vegetable oil, absolutes, and concretes. Typically, essential oils are highly complex mixtures of often hundreds of individual aroma compounds.

1. Agar oil, distilled from Agarwood (Aquilaria malaccensis). Highly prized for its fragrance.
2. Ajwain oil, distilled from the leaves of Bishop’s weed (Carum copticum). Oil contains 35-65% thymol.
3. Angelica root oil, distilled from the Angelica archangelica.
4. Anise oil, from the Pimpinella anisum, rich odor of licorice, used medicinally.
5. Asafoetida, used medicinally and to flavor food
6. Balsam oil, from the Myroxylon pereirae.
7. Basil oil is used in making perfumes, as well as in aromatherapy
8. Bay is used in perfumery; Aromatherapeutic for sprains, colds, flu, insomnia, rheumatism.
9. Bergamot oil, used in aromatherapy and in perfumes.
10. Black Pepper essential oil is distilled from the berries of Piper nigrum. The warm,soothing effect makes it ideal for treating muscle aches, pains and strains.
11. Buchu oil, made from the buchu shrub. Considered toxic and no longer widely used. Formerly used medicinally.
12. Birch is aromatheapeutic for gout, Rheumatism, Eczema, Ulcers.
13. Camphor is used for cold, cough, fever, rheumatism, arthritis
14. Cannabis flower essential oil, used as a flavoring in foods, primarily candy and beverages. Also used as a scent in perfumes, cosmetics, soaps, and candles.
15. Caraway oil, used a flavoring in foods. Also used in mouthwashes, toothpastes, etc. as a flavoring agent
16. Cardamom seed oil, used in aromatherapy and other medicinal applications. Extracted from seeds of subspecies of Zingiberaceae (ginger). Also used as a fragrance in soaps, perfumes, etc.
17. Carrot seed oil (essential oil), used in aromatherapy.
18. Cedarwood oil, primarily used in perfumes and fragrances.
19. Chamomile oil, There are many varieties of chamomile but only two are used in aromatherapy- Roman and German. Both have similar healing properties but German chamomile contains a higher level of azulin (an anti-inflammatory agent).
20. Calamus Root, used medicinally
21. Cinnamon oil, used for flavoring and medicinally.
22. Cistus species
23. Citronella oil, from a plant related to lemon grass is used as an insect repellent, as well as medicinally.
24. Clary Sage
25. Clove leaf oil, used as a topical anesthetic to relieve dental pain.
26. Coffee, used to flavor food.
27. Coriander
28. Costmary oil (bible leaf oil), from the Tanacetum balsamita
29. Costus Root, used medicinally
30. Cranberry seed oil, equally high in omega-3 omega-6 fatty acids, primarily used in the cosmetic industry.
31. Cubeb, used medicinally and to flavor foods.
32. Cumin oil/Black seed oil, used as a flavor, particularly in meat products. Also used in veterinary medicine.
33. Cypress
34. Cypriol
35. Curry leaf, used medicinally and to flavor food.
36. Davana oil, from the Artemisia pallens, used as a perfume ingredient and as a germicide.
37. Dill oil, chemically almost identical to caraway seed oil. High carvone content.
38. Elecampane, used medicinally.
39. Eucalyptus oil, historically used as a germicide. Commonly used in cough medicine, among other medicinal uses.
40. Fennel seed oil, used medicinally, particularly for treating colic in infants.
41. Fenugreek oil, used medicinally and for cosmetics from ancient times.
42. Frankincense oil, used for aromatherapy and in perfumes.
43. Galangal, used medicinally and to flavor food.
44. Galbanum
45. Geranium oil, used medicinally, particularly in aromatherapy, used for hormonal imbalance, for this reason geranium is often considered to be "female" oil.
46. Ginger oil, used medicinally in many cultures.
47. Goldenrod
48. Grapefruit oil, extracted from the peel of the fruit. Used in aromatherapy. Contains 90% limonene.
49. Henna oil, used medicinally
50. Helichrysum
51. Horseradish oil
52. Hyssop
53. Idaho Tansy
54. Jasmine oil, used for its flowery fragrance.
55. Juniper berry oil, used as a flavor. Also used medicinally, including traditional medicine.
56. Lavender oil is distilled from the lavender flower
57. Laurus nobilis
58. Lavender oil, used primarily as a fragrance. Also used medicinally.
59. Ledum
60. Lemon oil, similar in fragrance to the fruit. Unlike other essential oils, lemon oil is usually cold pressed. Used medicinally, as an antiseptic, and in cosmetics
61. Lemongrass. Lemongrass is a highy fragrant grass from India. In India, it is used to help treat fevers and infections. The oil is very useful for insect repellent.
62. Lime, anti septic, anti viral, astringent, aperitif, bactericidal, disinfectant, febrifuge, haemostatic, restorative and tonic. [18]
63. Litsea cubeba oil, lemon-like scent, often used in perfumes and aromatherapy.
64. Mandarin
65. Marjoram
66. Melaleuca See Tea tree oil
67. Melissa oil (Lemon balm), sweet smelling oil used primarily medicinally, particularly in aromatherapy.
68. Mentha arvensis oil/Mint oil, used in flavoring toothpastes, mouthwashes and pharmaceuticals, as well as in aromatherapy and other medicinal applications.
69. Mountain Savory
70. Mugwort oil, used in ancient times for medicinal and magical purposes. Currently considered to be a neurotoxin.
71. Mustard oil (essential oil), containing a high percentage of allyl isothiocyanate or other isothiocyanates, depending on the species of mustard
72. Myrrh oil, warm, slightly musty smell. Used medicinally.
73. Myrtle
74. Neem Tree Oil
75. Neroli is produced from the blossom of the bitter orange tree.
76. Nutmeg
77. Orange oil, like lemon oil, cold pressed rather than distilled. Consists of 90% d-Limonene. Used as a fragrance, in cleaning products and in flavoring foods.
78. Oregano oil, contains thymol and carvacrol, making it a useful fungicide. Also used to treat digestive problems.
79. Orris oil is extracted from the roots of the Florentine iris (Iris florentina) and used as a flavouring agent, in perfume, and medicinally.
80. Palo Santo
81. Parsley oil, used in soaps, detergents, colognes, cosmetics and perfumes, especially men’s fragrances.
82. Patchouli oil, very common ingredient in perfumes.
83. Perilla essential oil, extracted from the leaves of the perilla plant. Contains about 50-60% perillaldehyde.
84. Pennyroyal oil, highly toxic. It is abortifacient and can even in small quantities cause acute liver and lung damage.
85. Peppermint oil, used in a wide variety of medicinal applications.
86. Petitgrain
87. Pine oil, used as a disinfectant, and in aromatherapy.
88. Ravensara
89. Red Cedar
90. Roman Chamomile
91. Rose oil, distilled from rose petals, Used primarily as a fragrance.
92. Rosehip oil, distilled from the seeds of the Rosa rubiginosa or Rosa mosqueta. Used medicinally.
93. Rosemary oil, distilled from the flowers of Rosmarinus officinalis. Used in aromatherapy, topically to sooth muscles, and medicinal for its antibacterial and antifungal properties.
94. Rosewood oil, used primarily for skin care applications. Also used medicinally.
95. Sage oil, used medicinally.
96. The spice star anise is distilled to make star anise oil
97. Sandalwood oil, used primarily as a fragrance, for its pleasant, woody fragrance
98. Sassafras oil, from sassafras root bark. Used in aromatherapy, soap-making, perfumes, and the like. Formerly used as a spice, and as the primary flavoring of root beer, inter alia.
99. Savory oil, from Satureja species. Used in aromatherapy, cosmetic and soap-making applications.
100. Schisandra oil, from Schisandra chinensis, used medicinally.
101. Spearmint oil, often used in flavoring mouthwash and chewing gum, among other applications.
102. Spikenard, used medicinally.
103. Spruce
104. Star anise oil, highly fragrant oil using in cooking. Also used in perfumery and soaps, has been used in toothpastes, mouthwashes, and skin creams. 90% of the world's star anise crop is used in the manufacture of Tamiflu, a drug used to treat influenza, and is hoped to be useful for avian flu
105. Tangerine
106. Tarragon oil, distilled from Artemisia dracunculus, used medicinally.
107. Tea tree oil, distilled from Melaleuca alternifolia, used medicinally. Being a powerful antiseptic, antibacterial and antiviral agent, tea tree's ability to fight infection is second to none.
108. Thyme oil, used medicinally.
109. Tsuga
110. Turmeric, used medicinally and to flavor food
111. Valerian, used medicinally
112. Vetiver oil (khus oil) a thick, amber oil, primarily from India. Used as a fixative in perfumery, and in aromatherapy
113. Western red cedar
114. Wintergreen
115. Yarrow oil is used medicinally, to relieve joint pain
116. Ylang-ylang
117. Zedoary, used medicinally and to flavor food

source : wikipedia.org