In Osny, turnout was lower than in 90% of compared French communes
Laurent Achite-Henni has been mayor of Osny since March 21, 2026, elected by the 33 members of the municipal council. At the March 2026 municipal elections, OSNY ENSEMBLE VERS LE FUTUR won 26 of the 33 seats in the first round on March 15, 2026, with 55.2% of the votes. Osny is part of the Communauté d'agglomération de Cergy-Pontoise.
March 2032
Councils are elected for six years; the council elects the mayor.
Register to vote ↗Throughout this page, the median in Val-d'Oise and the France median are the median of compared communes (those with an overall grade), each figure its own median.
What stands out about Osny’s town hall
Won in the first round
OSNY ENSEMBLE VERS LE FUTUR won 55.2% of the votes on March 15, 2026, more than half, so there was no second round; 2 lists stood. It took 26 of the 33 seats: half the seats as the list ahead, and its share of the rest. The other lists share the remaining 7. Who’s in charge ↓
Turnout below most communes
44.7% of registered voters in Osny voted on March 15, 2026: lower than in 90% of compared French communes. The median of compared communes in Val-d'Oise was 52.1%; across France, 57.4%. 2026 elections ↓
Results as the Interior ministry published them; accounts from the DGFiP via OFGL. Nothing here is graded.
The council the voters chose
Seats as the March 2026 results gave them, one dot a seat.
- OSNY ENSEMBLE VERS LE FUTUR264 community seats
- OSNY INTENSEMENT71 community seat
As elected in the first round, March 15, 2026.
The list that comes first gets half the seats; the rest are shared in proportion among the lists with 5% or more, the winner included. So the winning list always has a majority. The same vote gave Osny 5 seats on the council of the Communauté d'agglomération de Cergy-Pontoise (community seats).
Source: Interior ministry, 2026 municipal election results (March 15 and 22), subject to corrections and appeals.
4 authorities share the work
The commune is the tier closest to residents; the intercommunality, the département and the région do the rest.
Births, marriages and deaths, the electoral roll, nursery and primary schools, local roads, planning permission, the municipal police, and what else the council takes on.
Mayor: Laurent Achite-Henni · 33 councilors
The services its communes share: usually waste collection, economic development and planning documents; often water and local buses.
Social aid (RSA, care for older and disabled people, child protection), collèges, the département’s roads, and funding for fire and rescue.
Lycées, regional trains (TER) and coaches, economic development and job training.
Who to ask
The usual split of powers (service-public.fr); an intercommunality’s exact remit varies, so check its website for waste, water and buses.
Membership: COG 2026 (INSEE); intercommunality type: BANATIC, January 2025. What each tier does: service-public.fr.
From the mayor to the intercommunality
The officials as the Interior ministry’s register lists them, and the council by list.
- 1Mayorsince March 21, 2026Laurent Achite-Henni
- 2Deputy mayors9 adjoints, elected by the councilJean Marc LeclercSophie DemangeChristophe CarreraChloé GriardEric VincentIsabel PaisJean-Louis BovierIsabelle Libert+1 more
- 3Osny municipal council33 seats by listOSNY ENSEMBLE VERS LE FUTUR 26 · OSNY INTENSEMENT 7
- 4Communauté d'agglomération de Cergy-PontoiseOsny holds 5 seatsCommunity councilors are drawn from the council lists in the same vote.
Source: Interior ministry, national register of elected officials (RNE), August 11, 2026.
The 33 members of the Osny municipal council
The mayor and 9 deputy mayors first, then the councilors.
| Name | Office | Since |
|---|---|---|
| Laurent Achite-Henni | Maire | March 21, 2026 |
| Jean Marc Leclerc | 1er adjoint au Maire | March 21, 2026 |
| Sophie Demange | 2ème adjoint au Maire | March 21, 2026 |
| Christophe Carrera | 3ème adjoint au Maire | March 21, 2026 |
| Chloé Griard | 4ème adjoint au Maire | March 21, 2026 |
| Eric Vincent | 5ème adjoint au Maire | March 21, 2026 |
| Isabel Pais | 6ème adjoint au Maire | March 21, 2026 |
| Jean-Louis Bovier | 7ème adjoint au Maire | March 21, 2026 |
| Isabelle Libert | 8ème adjoint au Maire | March 21, 2026 |
| Laurent Chartier | 9ème adjoint au Maire | March 21, 2026 |
Show the full council (33)
| Name | Office | Since |
|---|---|---|
| Laurent Achite-Henni | Maire | March 21, 2026 |
| Jean Marc Leclerc | 1er adjoint au Maire | March 21, 2026 |
| Sophie Demange | 2ème adjoint au Maire | March 21, 2026 |
| Christophe Carrera | 3ème adjoint au Maire | March 21, 2026 |
| Chloé Griard | 4ème adjoint au Maire | March 21, 2026 |
| Eric Vincent | 5ème adjoint au Maire | March 21, 2026 |
| Isabel Pais | 6ème adjoint au Maire | March 21, 2026 |
| Jean-Louis Bovier | 7ème adjoint au Maire | March 21, 2026 |
| Isabelle Libert | 8ème adjoint au Maire | March 21, 2026 |
| Laurent Chartier | 9ème adjoint au Maire | March 21, 2026 |
| Jennifer Balland | Conseiller municipal | March 15, 2026 |
| Jean-Yves Caillaud | Conseiller municipal | March 15, 2026 |
| Martine Caussin | Conseiller municipal | March 15, 2026 |
| Fares Chabani | Conseiller municipal | March 15, 2026 |
| Clémence Chauvet | Conseiller municipal | March 15, 2026 |
| Sandrine Chevallier | Conseiller municipal | March 15, 2026 |
| Christiane Courel | Conseiller municipal | March 15, 2026 |
| Jean-Michel Courvalet | Conseiller municipal | March 15, 2026 |
| Danièle Dubreil | Conseiller municipal | March 15, 2026 |
| Matilde Faustino-Carvalho | Conseiller municipal | March 15, 2026 |
| Marie-Claire Launay | Conseiller municipal | March 15, 2026 |
| Jean-François Maillard | Conseiller municipal | March 15, 2026 |
| Mickaël Marc | Conseiller municipal | March 15, 2026 |
| Florian Marguerie | Conseiller municipal | March 15, 2026 |
| Carole Montassier | Conseiller municipal | March 15, 2026 |
| Marie Munchow | Conseiller municipal | March 15, 2026 |
| Valérie Neveu | Conseiller municipal | March 15, 2026 |
| Christophe Poitou | Conseiller municipal | March 15, 2026 |
| Tatiana Priez | Conseiller municipal | March 15, 2026 |
| Jean-Marc Segura | Conseiller municipal | March 15, 2026 |
| Christian Sorin | Conseiller municipal | March 15, 2026 |
| Virginie Tinland | Conseiller municipal | March 15, 2026 |
| Gérard Villette | Conseiller municipal | March 15, 2026 |
Names and offices as the Interior ministry’s national register of elected officials (RNE) published them on August 11, 2026, written as it writes them. Public role only. Later resignations and replacements aren’t shown.
The council: same source as Who represents Osny, above.
How Osny voted in March 2026
2 lists stood; one won more than half the votes in the first round.
4,609 votes cast for a list
4,895 of 10,945 registered voters in Osny voted.
203 blank and 83 spoilt ballots, not counted in the shares.
Turnout, first round · March 15, 2026
Shares are of the votes cast for a list, leaving out blank and spoilt ballots. Lists in vote order; the colors only tell the lists apart.
2026 elections: same source as Who’s in charge, above.
Osny spends €1,545 per resident a year
The commune’s consolidated accounts: main and annexed budgets, transfers between them removed.
Per resident, 2025 · against compared communes
Spending and debt per resident, 2018 to 2025
Osny owed €15M at the end of 2025, €850 per resident, higher than in 58% of compared French communes, equal to 75% of a year’s running costs.
Show year by year
| Year | Spending | Investment | Debt | Debt in all |
|---|---|---|---|---|
| 2025 | €1,545 | €417 | €850 | €15M |
| 2024 | €1,561 | €476 | €957 | €16.7M |
| 2023 | €1,530 | €463 | €1,063 | €18.4M |
| 2022 | €1,870 | €851 | €1,080 | €19.1M |
| 2021 | €1,634 | €654 | €843 | €14.9M |
| 2020 | €1,141 | €187 | €700 | €12M |
| 2019 | €1,225 | €244 | €764 | €13.1M |
| 2018 | €1,184 | €228 | €814 | €14.3M |
Source: OFGL, consolidated commune accounts 2018–2025 (DGFiP); 2025 provisional.
The 20th highest debt per resident of 41 communes its size
The 40 compared communes nearest in population, debt per resident at the end of 2025.
Lowest: Écully, €0. Highest: Carvin, €3,332.
Have a say in Osny
French citizens register online or at the town hall; citizens of other EU countries can vote in municipal elections too.
service-public.fr ↗See where you’re registered and which polling station is yours.
service-public.fr ↗Council meetings are public; the agenda and minutes are posted at the town hall and usually on its website.
service-public.fr ↗Opening hours, address and phone number of the mairie of Osny in the public services directory.
lannuaire.service-public.fr ↗Who can stand, how lists are formed and the deadlines, from the Interior ministry.
interieur.gouv.fr ↗What this data can and can’t tell you
- Mayors and councilors. From the Interior ministry’s national register of elected officials (RNE) as published on August 11, 2026: name, office and start dates, nothing else. The register counts a mayor as a councilor too; the page counts each person once. It isn’t a live roll: resignations and replacements after that date aren’t shown, and no party is inferred for any official.
- How the council is elected. Since March 2026 every commune elects its council from lists (a 2025 law extended list voting to communes under 1,000). A list with more than half the votes in the first round wins; otherwise lists with 10% or more can go on to a second round, where the list ahead wins. It gets half the seats, and the rest are shared in proportion among lists with 5% or more. The council then elects the mayor and the deputy mayors.
- The label beside a list. The political nuance the prefecture gave the list for the ministry’s results (Divers droite, Union de la gauche…), shown as published. It isn’t the list’s own description; many lists, most in small communes, have none.
- The commune’s money. OFGL’s consolidated accounts from the DGFiP, 2018 to 2025; 2025 is provisional. Spending and investment leave out loan repayments; running costs are part of spending. Debt is what was owed at the end of the year.
- Per resident. Divided by the DGFiP’s population for that year (population totale, which counts some people, such as boarding students, in two communes), so it can differ from the census figure elsewhere on the site.
- The medians. Beside the town’s figure, the median of compared communes in its département and in France (those with an overall grade). A commune’s spending follows its size and its role: one that runs a pool or a theater for the villages around it spends more per resident.
Questions about Osny’s town hall
Who is the mayor of Osny?
Laurent Achite-Henni, mayor since March 21, 2026, according to the Interior ministry’s register of elected officials (August 11, 2026).
How many councilors does Osny have?
The Osny municipal council has 33 members, the mayor and 9 deputy mayors included.
Who won the 2026 municipal elections in Osny?
OSNY ENSEMBLE VERS LE FUTUR, in the first round on March 15, 2026, with 55.2% of the votes; it holds 26 of the 33 seats.
What was the turnout in Osny?
44.7% of registered voters voted in the first round on March 15, 2026; the median of compared French communes was 57.4%.
When are the next municipal elections in Osny?
Councils are elected for six years, so the next general municipal elections are due in March 2032. A council can be re-elected sooner if it loses too many members.
How much debt does Osny have?
€15M at the end of 2025, €850 per resident; the median of compared French communes was €748.
Which intercommunality is Osny part of?
Osny is part of the Communauté d'agglomération de Cergy-Pontoise, which runs the services its communes share.
Sources: Interior ministry RNE, August 11, 2026 · Interior ministry, municipal results 2026 · OFGL consolidated commune accounts 2018–2025 · INSEE COG 2026 and BANATIC (January 2025) for the intercommunality. Under the Licence Ouverte / Open Licence 2.0 (Etalab).
Contains public sector information under the Licence Ouverte / Open Licence 2.0 (Etalab): INSEE, DGFiP, the Interior Ministry’s statistics service (SSMSI), the Ministry of Education (DEPP), the Health Ministry’s statistics service (DREES) and the Housing Ministry (Carte des loyers). Commune boundaries: IGN Admin Express.