Last modified: 15 March 2021
Deaths in reigning and non-reigning royal houses of the year 2018.
* = New
| Date | Name | Age | Place |
| * 2 January | Prince Regent Sauryavong Savang of Laos | 80 | Créteil, Val-de-Marne, France |
| 5 January | Countess Ursula zu Pappenheim | 91 | Eichstätt, Germany |
| 9 January | Fürstin Charlotte von Quadt zu Wykradt und Isny née Princess of Bavaria | 86 | |
| 27 January | Countess Claudia von Colloredo-Mannsfeld née Pless | 52 | |
| 28 January | Sheikha Hessa bint Mohammed bin Khalifa Al Nahyan of Abu Dhabi (UAE) | ||
| 1 February | Prince Karl-Heinz zu Hohenlohe-Oehringen né Sassen | 77 | Phuket, Thailand |
| 1 February | Prince Mohammed bin Abdulrahman bin Musaed bin Abdulrahman Al Saud of Saudi Arabia | ||
| 6 February | Princess Antoinette zu Salm-Salm | 58 | Bonn, Germany |
| 10 February | The mother of Prince Faysal bin Musa’id bin Abd al-Rahman of Saudi Arabia | ||
| 13 February | Prince Henrik of Denmark né de Laborde de Monpezat | 83 | Fredensborg Palace, Fredensborg, Denmark |
| 14 February | Prince Abdulaziz bin Bandar bin Mohammed bin Abdulaziz Al Saud of Saudi Arabia | ||
| 16 February | The mother of Prince Faysal bin Fahd bin Muhammad of Saudi Arabia | ||
| 23 February | Prince Carlos von Hohenzollern | 39 | Intercontinental Hotel, Frankfurt am Main, Germany |
| February | Alessandra Schoenburg Tanturri née Princess zu Schönburg-Waldenburg | Rome, Italy | |
| 1 March | Sheikha Al Jazi Al Ahmad Al Sabah of Kuwait | 86 | |
| 6 March | Princess Cassandra zur Lippe-Weissenfeld | 74 | Madison Heights, Virginia, USA |
| 8 March | Count Friedrich zu Castell-Castell | 67 | |
| 12 March | Prince Bandar bin Khalid bin Abdulaziz Al Saud of Saudi Arabia | 82 or 83 | |
| * 17 March | Princess Mathilde of Saxony (Sachsen-Coburg und Gotha) | 82 | Sistrans, Austria |
| 30 March | The mother of Prince Hassan bin Musa’id bin Abd al-Rahman of Saudi Arabia | ||
| 3 April | Sheikh Ahmed bin Mohammed bin Sultan al Qasimi of Sharjah (UAE) | ||
| 3 April | Countess Marie-Thérèse von Waldburg zu Zeil und Hohenems née Countess Nemes de Hidvég et Oltszem | 52 | Kempfenhausen, Germany |
| * 6 April | Prince Bahman Pahlavi | 67 | La Verrière, Yvelines, France |
| 6 April (suicide) | Inkhosikati LaMasango née Senteni Masango (Swaziland) | ||
| 12 April | Countess Maria Magdalena von und zu Trauttmansdorff-Weinsberg “Madeleine” | 92 | |
| 5 May | Fürst Franz Alexander von Isenburg | 74 | München, Germany |
| 9 May (car crash) | Duke Friedrich von Württemberg | 56 | Ebenweiler, Germany |
| 10 May (car accident) | Hubertus Stephan (Hohenlohe-Langenburg) | 47 | Aurach, Austria |
| 10 May | Princess Maria Karin zu Stolberg-Wernigerode née Freiin von Düring | 83 | Bad Salzhausen, Germany |
| 10 May | Ferdinand Wutholen (Tuscany) | 91 | |
| 13 May | Kanwar Ratanjit Singh (Kapurthala) | 77 | Simla, India |
| 28 May | Count Hans von der Goltz (Solms-Laubach) | 91 | |
| 28 May (burial) | Princess Munira bint Abd al-Aziz bin Abd al-Muhsin (Saudi Arabia) | ||
| 1 June | Josephine Ruby Trevorrow (Johor, Malaysia) | 82 | King Edward VII’s hospital, London, UK |
| 2 June | Desmond de Silva (Yugoslavia) | 78 | |
| 5 June | Sheikh Abdullah bin Khalid bin Ali al Khalifa of Bahrain | 95 or 96 | |
| 9 June | Sheikha Hala bint D’aji al Khalifa of Bahrain | ||
| 9 June (riding accident) | Prince Georg-Constantin von Sachsen-Weimar und Eisenach | 41 | Apethorpe Palace, Northamptonshire, UK |
| 9 June | Princess Maria Fernanda Eudoxia von Thurn und Taxis | 90 | |
| 13 June | Countess Christiana von Schönborn-Buchheim née von Mautner Markhof | 90 | |
| 17 June (car crash) | Ouk Phalla (Cambodia) | 39 | Hospital, Sihanoukville |
| 19 June | Princess Elisabeth of Denmark | 83 | Træningscenter Fortunen, Lyngby, Denmark |
| * 22 June | Princess Lavinia-Mata-‘o Taone of Tonga | 66 | Auckland, New Zealand |
| 25 June | Prince Friedrich-Carl zu Waldeck und Pyrmont | 84 | |
| June | Siale ‘ataongo Puloka (Tonga) | ||
| 1 July | Sheikh Hamad bin Mohammed Al Qasimi of Ras Al Khaimah (UAE) | ||
| 3 July | Rajmata Krishna Kumari of Jodhpur, the last ruling Maharani of Jodhpur | 92 | |
| 6 July | The mother of Princess Fahda bint Saud bin Abdulrahman Al-Saud of Saudi Arabia | ||
| 7 July | Prince Michel de Bourbon de Parme | 92 | Neuilly-sur-Seine, Hauts-de-Seine, France |
| 11 July | Prince Abdul Ali Seraj of Afghanistan | 72 | Milford, Connecticut, USA |
| 15 July | Count Friedrich-Ernst zu Solms-Laubach | 86 | |
| 17 July | Evgeniy Petrovich Gruzinsky (Georgia) | 70 or 71 | Moscow, Russia |
| 20 July | Archduchess Maria of Austria née Princess zu Löwenstein-Wertheim-Rosenberg | 82 | Vienna, Austria |
| 21 July | Elisabeth Margarete Wolf née Countess zu Castell-Castell | 89 | |
| 23 July | Duke Carl Gregor zu Mecklenburg | 85 | Villa Silberburg, Hechingen, Germany |
| 27 July | Princess Ingeborg zu Waldeck und Pyrmont née von Biela | 86 | Bad Arolsen, Germany |
| 30 July | Andreas Grunwald (Pappenheim) | 53 | |
| 3 August (burial) | Baroness Elisabeth Winspeare Guicciardi née Princess von und zu Liechtenstein | 86 | |
| 9 August | Mehrdad Pahlbod (Iran) | 101 | Los Angeles, California, USA |
| 10 August | Princess Maria Josefa of Saxony | 89 | Bad Wiessee, Germany |
| 13 August | Sheikha Fareeha Al-Ahmad Al-Jaber Al-Sabah of Kuwait | 74 | |
| 22 August | The mother of Prince Muqrin bin Saud bin Abdul Aziz Al-Saud of Saudi Arabia | ||
| 28 August | Duchess de Looz-Corswarem née Christiane Lacarrière | 98 | Croissy-sur-Seine, Yvelines, France |
| 12 September | Duke Friedrich August von Oldenburg | 65 | Nanyuki, Kenya |
| 13 September | Count Christian Carl zu Stolberg-Wernigerode | 75 | Frankenthal, Germany |
| 1 October (burial) | Princess Noura bint Turki bin Abdullah bin Saud bin Faisal Al Saud of Saudi Arabia | Mecca, Saudi Arabia | |
| 19 October | Vishalakshi Devi (Mysore) | 55 | Hospital, Bengaluru, India |
| 31 October (?) | Sheikh Salman Mohammad Salman Al Humoud Al Salman Al Sabah of Kuwait | ||
| 1 November | Countess Ilse von Schönborn née Gemündt | 96 | |
| 6 November | Princess Ida zu Windisch-Graetz née Countess von Seilern und Aspang | 99 | Vienna, Austria |
| 8 November | Count and Edler Herr Erik von Platen Hallermund | 79 | |
| 11 November | Maharani Deepinder Kaur (Faridkot) | 82 | Raj Mahal, Faridkot, India |
| 15 November | Fürst Alexander von Schönburg-Hartenstein | 88 | |
| 20 November | Princess Carmen of Bourbon-Two Sicilies | 94 | Fréjus, Var, France |
| 3 December | Shaikha Bazza Mohammed Al-Ali Al-Malik Al-Sabah of Kuwait | 82 | |
| 11 December | Shaikha Noora bint Isa bin Salman Al Khalifa of Bahrain | ||
| 19 December | Count Engelbert zu Ortenburg | 79 | Post Inn Village, Oakville, Canada |
| 22 December | Prince Talal bin Abdulaziz Al Saud of Saudi Arabia | 87 | |
| * 29 December | Princess Ponnaraingsey Norodom of Cambodia | 75 | Luxembourg |