Neptune is smoke and mirrors. It conjures visions that are enticing and horrifying in turn.
In astrology, Neptune rules all things ephemeral and illusory. It is a planet of hope and despair, bringing wild fantasies, fervent faith, technicolour illusions and destructive delusions. Neptune’s visions are always intangible and inscrutable. They feel so real, like you could just reach out and touch them – but then they dissipate like smoke from a snuffed candle.
Invisible to the naked eye, the planet Neptune looms on the very edge of our solar system. It marks the boundary between the orderly procession of planets around the Sun, and the wild rogues roaming the vast reaches of the Kuiper Belt.
Neptune’s phantasmic qualities make it one of the most dangerous planets in terms of its effect on both individuals and groups. It isn’t considered a malefic or benefic planet in the traditional sense, because it is not part of traditional astrology – having only been discovered in 1846 – but it can still bring about great destruction and hardship.
This destruction is very different than that wrought by Mars, which prefers fire, blood and direct, knife-to-the-heart forms of violence. It’s also different than the ruination wrought by Saturn, which will wreck you through back-breaking trials and long-term suffering. And it’s different than the annihilation wrought by Pluto, which brings about obliteration through cataclysm and calamity.
Neptune never takes a direct approach. It will lure its victims with a siren song and promises of riches, beauty, transcendence. It will conjure up images that seem so real, they entice people to abandon everything they’ve built, betray their friends and family, and destroy themselves chasing after that vision – only to have it all melt away like droplets on hot asphalt. Neptune wreaks havoc by confusion and mystery.
Yet Neptune can also inspire great heights of human spirit and achievement. When its energies are harnessed productively, Neptune acts as Muse, guiding one to create inspiring and beautiful works of art, or to connect on the deepest levels with others, or to transcend body and mind into oneness with all.
These are the main astrological significations of Neptune:
- Illusion
- Delusion
- Fantasy
- Hopes
- Confusion
- Dissolution
- Collectives
Astrologers diverge on some key points related to Neptune. Those who practice traditional astrology (such as myself) do not assign Neptune to the schema of sign rulership. Neptune is invisible to the naked eye and was not known to the ancients, and therefore not included in the Thema Mundi.
Modern astrologers assign Neptune as the ruler of Pisces, supplanting its traditional ruler, Jupiter. At first glance, Neptune seems to align well with the watery sign of the twin fishes. The planet Neptune is an ice giant with a deep blue hue, thanks to a high concentration of methane in its atmosphere – so it looks like a vast, swirling ocean. Accordingly, its astronomical namesake is the Roman god of the sea (whom the Greeks called Poseidon), furthering its connection with water and suggesting an alignment with the mutable water sign of Pisces.
However, Neptune’s astrological significations really don’t fit with the Roman ocean god. As the signifier of dreams and illusions, fantasies and phantasms, imagination and delusion, Neptune would have been better served by a different name. Morpheus, the Roman god of dreams, is far more appropriate.
Furthermore, modern astrologers also conflate Neptune with some 12 Letter Alphabet significations of Jupiter, which are themselves a conflation of Sagittarius with the ninth house and Pisces with the twelfth house. They say that Neptune is aligned with spirituality and religion (9th house), as well as self-deception and mental illness (12th house); also, that Neptune inspires and unites (Jupiter).
But in traditional astrology, Jupiter rules Pisces. In this sign, he is the benevolent, all-encompassing king on an ever-shifting throne of ocean surf. In Pisces, Jupiter unites all things, the way water will always seep into the tiniest cracks of dry earth, dissolving the boundary between earth and liquid. These droplets melt into the soil, rendering it fertile, life-giving loam. Jupiter in Pisces penetrates to the very essence of things, as magnanimous truth-bringer and life-giver, whose swirling waters unite all. This is why Venus is exalted here; she thrives in Jupiter’s fertile, connective sea, bringing inspiration and beauty.
Neptune does not function in this benefic way. It signifies groups of people, who may seem united under a common vision. But this only lasts until the hallucination, hope, fantasy or drug wears off. Neptune may seem to inspire transcendence, but only as a byproduct of illusions that may also drive you mad.
So, it all gets really muddy, really quickly. Neptune has also been in Pisces for nearly 15 years (from 2011 to early 2026). This has furthered the conflation of Neptune with Pisces/Jupiter/9th house/12th house in current discourse. Neptune’s shift into Aries in February 2026 should hopefully dispel some of these misconceptions.
The circumstance of Neptune’s discovery is a wonderful example of the Neptunian principle at work. The planet Neptune was discovered in 1846 through the application of theoretical astronomy. Two astronomers, Urbain Le Verrier and John Adams, predicted Neptune’s existence after observing disturbances in the planet Uranus’ orbit. They each made this prediction independently from one another. In 1846, German astronomer Johann Galle verified their prediction by aiming a telescope at the part of the sky indicated by Le Verrier and Adams’ mathematical calculations. Lo and behold, Neptune winked back.
I think this method of discovery factored into Neptune’s association with fantasy and illusion, with unseen and intangible things that can nevertheless describe what is very real – just like how Neptune existed only in the imaginal until we found physical proof of it.
This origin story fits so perfectly with how Neptune operates in astrology. It was out there but invisible, causing real effects on its neighbour. Astronomers discovered it through an intangible method – mathematical theory – that nevertheless had a very tangible outcome.
There’s a lot we still don’t know about Neptune on an astronomical level, which also fits its astrological meaning. It’s an ice giant like Uranus, yet appears to be much more active than its icy neighbour, despite being so much farther from the Sun. Neptune has the strongest winds of any planet in the solar system, which cause huge, dark storms on its surface that appear and disappear at random. Very Neptunian!
In mundane/geopolitical astrology, Neptune rules collectives – large groups of people. You will find a number of sources stating that Neptune rules socialism, but in my experience, this isn’t quite right. Socialism is concerned with the welfare of groups of people, so Neptune can certainly be an indicator of this political ideology. However, I’ve found that Neptune simply represents the collective principle in a broad sense, which could be socialism but could also be other forms of collective government, such as fascism or communism. Neptune also represents groups of people that unite under a common cause, including activists and terrorists alike.
Neptune also signifies drugs, cults, mobs, gangs, fraud, thievery and hidden activity – illicit or otherwise. Basically, it’s anything where you have groups of people, especially those operating under illusions or delusions and/or in pursuit of an intangible but alluring goal.
I’d like to conclude this article with two quotes on the meaning of Neptune in astrology. The first is a passage on how Neptune operates in natal astrology, as described by Robert Hand in his book Planets in Transit (1976):
“Neptune is usually one of the most difficult planetary influences to handle. It causes life to become confusing and unclear, and under its influence people often believe what is not true. At the same time, Neptune often has an ego-denying influence, which may make you feel discouraged, futile, undeserving and unworthy. Or it can lead you to perform great acts of selflessness and self-martyrdom. Neptune can also expose you to some extremely beautiful and ideal influences, which may not always be real but are worthwhile because of their beauty. Everything that man dreams of making come true as well as everything that man thinks is true, even though it isn’t, comes under the influence of Neptune.”
The second quote is from Richard Tarnas, in his seminal work Cosmos and Psyche (2006):
“Neptune is associated with the transcendent, spiritual, ideal, symbolic, and imaginative dimensions of life; […] with all that which transcends the limited literal temporal and material world of concretely empirical reality: myth and religion, art and inspiration, ideals and aspirations, images and reflections, symbols and metaphors, dreams and visions, mysticism, religious devotion, universal compassion. … with tendencies towards illusion and delusion, deception and self-deception, escapism, intoxication, psychosis, perceptual and cognitive distortions, conflation and confusion, projection, fantasy; with the bedazzlement of consciousness whether by gods, archetypes, beliefs, dreams, ideals, or ideologies; with enchantment, in both positive and negative sense.”