Álmos (died 1129) was a Hungarian prince, the son of King Geza I of Hungary, brother of King Kálmán. He held several governmental posts in the Kingdom of Hungary.

Between 1084 and 1091 he was the duke of Slavonia; between 1091 and 1095 he was named King of Slavonia (eastern Croatia). In 1095 Kálmán dethroned Álmos, making him the duke of the apanage Nitrian duchy (Tercia pars regni) instead.

Álmos, supported by Germany and Bohemia, came in conflict with Kálmán in 1098, after Kálmán had declared himself the king of the whole of Croatia in 1097 (crowned in 1102). On August 21, 1104 Álmos married Predslava, the daughter of Svyatopolk II of Kiev.

Kálmán made peace with Álmos in 1108, but only to have Álmos and his son Béla imprisoned in 1108 or 1109 and then blinded to prevent them from becoming the future king. After this he went on to live in seclusion at the monastery of Dömös founded by himself until his death, but his son would succeed as king of Hungary.

Álmos was the last duke of Nitra (in Hungarian Nyitra), his removal also marks the end of the Nitrian Frontier Duchy and thus a full integration of the complete territory of today's Slovakia into Hungary.

Family
On August 21, 1104 Álmos married Predslava, the daughter of Svyatopolk II of Kiev and has children:
1. Adelaide, (b. c. 1105/07 – 15 September 1140); Married 1123 with Duke Sobeslav I of Bohemia
2. Béla II of Hungary
3. Hedwig, married 1132 with Duke Adalbert of Austria (1107 – 1137/38)