The raid on Mljet (Serbo-Croatian: Desantni prepad na Mljet) was an amphibious raid carried out by the Yugoslav Partisans in April 1944 against the German garrison on the Dalmatian island of Mljet. Occupied by Italian Forces during the Invasion of Yugoslavia in April 1941, the island briefly came under Partisan control following the Armistice of Cassibile in September 1943. It was soon captured by German Forces during their anti-Partisan operations aimed at securing the coastal areas of Yugoslavia previously occupied by the Italians. By early 1944, almost all of the Dalmatian islands were under German control, the exception being Vis which soon became a Partisans stronghold from which the Partisans and Allied Commandos would begin launching raids against German island garrisons.

The raid on Mljet was planned as a diversionary attack with the goal of confusing and tying-up German Forces while the Partisans conducted a much larger raid against the Germans on Korčula. The Partisan plan was to land three battalions of the 1st and 11th Brigades on two locations on the south of Mljet one day before the raid on Korčula would commence. A significant obstacle for the Partisans was the lack of appropriate vessels to transport the raiding party. With Allied Forces declining to take part in the raid, the Partisans would carry-on using motor-powered sailboats and small galleys escorted by two armed ships, both of which were in fact lightly armed civilian vessels. Because the distance from Vis to Mljet is 64 nautical miles (119 kilometres) and the Partisan ships were unable to attain a speed greater than 4–5 knots (7.4–9.3 km/h; 4.6–5.8 mph), it was impossible for them to reach Mljet in a single night and conduct the transport by sea under the cover of darkness. Instead, it was decided to carry it out in two legs: first by departing for Lastovo during the first night and continuing to Mljet during the second night.

The raiding party departed Vis on 19 April 1944 with 16 vessels organized in two convoys. They reached Skrivena Luka on Lastovo at 05:30 of 20 April after which the troops disembarked and the ships were camouflaged along the cove. The convoys departed Lastovo during the second night, reaching Mljet shortly after midnight of 21 April. At 06:00, the Partisans engaged German Forces which consisted of one or two companies numbering around 200 men. The Partisans were successful in overrunning the German positions, though one was soon counterattacked and retaken by the Germans. Two companies of German reinforcements arrived during the night of 21/22 April but didn't engage in major actions. With their goals largely achieved, the Partisans retreated to the Sutmiholjska cove where they boarded their ships and departed for Lastovo during the night of 22/23 April.

Although the German garrison wasn't completely destroyed, the Partisans were successful in inflicting heavy casualties and diverting three companies of their reserves to Mljet. During the night of 22 April, the Partisans began their main effort on Korčula by landing six battalions on the island. The raid proved to be highly successful, with German Forces suffering hundreds of killed and captured in action and losing large amounts of materiel.

Following the Axis Invasion of Yugoslavia in April 1941, Dalmatia was partitioned between the Kingdom of Italy and the newly established Axis puppet state of Independent State of Croatia (Croatian: Nezavisna država Hrvatska – NDH). In accordance with the treaties of Rome signed on 18 May 1941, Split, Šibenik, Ravni Kotari and all of the Dalmatian islands excluding Brač and Hvar were annexed by the Kingdom of Italy. The Italian surrender in September 1943 gave way to a large scale Partisan uprising in Dalmatia; The Partisans were successful in taking control of most of Dalmatia and all of its islands, capturing large amounts of materiel of the Royal Italian Army in the process. Meanwhile, faced with the possibility of an Allied amphibious landing along the eastern Adriatic, the Germans quickly began repositioning their forces with the goal of securing the areas previously held by the Italian Forces. The 114th Jäger Division was tasked with capturing northern Dalmatia while the 7th SS Volunteer Mountain Division Prinz Eugen was tasked with capturing central Dalmatia and its islands. By early September, German Forces secured Knin continuing their advance towards Drniš, Zadar an Šibenik, securing all three with no resistance by the surrendering Italian Forces. Heavy fighting between German and Partisan Forces would erupt on the approaches to Split, a significant administrative and political center of Dalmatia also housing one of the largest Italian garrisons in Dalmatia. German Forces finally captured Split on 27 September. Despite German advances, with an influx of thousands of new fighters and captured materiel in the aftermath of the Italian surrender, the Partisans were able to create nine Dalmatian-based brigades, culminating in the creation of the 8th Corps on 7 October 1943.

Following the occupation of Split, German Forces launched operation Operation Herbstgewitter with the goal of securing the remaining coastline and the islands. The first phase of the operation commenced on 23 October with German landings on Pelješac. After twelve days of fighting and suffering over 250 killed, wounded or missing, the Partisans retreated to Podgora and Korčula. German Forces continued their advance and on 22 December began their assault on Partisan-held Korčula. In three days of the ensuing fighting, the Partisans suffered heavy casualties before retreating to Hvar and Vis; of the 1057 fighters of the 13th Brigade, only 525 were evacuated from Korčula while the 1st Overseas Brigade suffered 300 killed, wounded or missing. The final leg of Operation Herbstgewitter commenced on 31 December with German Forces landing on Mljet. The island was captured without resistance as the elements of the 13th Brigade and the Orjen Partisan Detachment which were located on the island were evacuated to Vis beforehand.

Following the German occupation of Korčula and facing an enemy which possessed technical and numerical superiority, the Partisans decided to abandon the defense of Brač, Hvar and Šolta and concentrate their defensive efforts on Vis. Vis was heavily fortified and defended by the 26th Division, the Partisan Navy and Allied assets, becoming a central line of communication to Allied Forces in Italy and a staging ground for future efforts of disrupting German coastal defences. Beginning in early 1944, Partisan and Allied Forces began carrying out amphibious raids against German island garrisons. Both Partisan and Allied Forces carried out several small-scale raids on German positions on Hvar. Allied Commandos carried out a highly successful raid on Šolta on 18 March, followed by another combined Partisan-Allied raid on Hvar in late March.

The raid on Mljet was planned as a diversionary attack while the main effort was concentrated on German Forces on Korčula. The raid was planned to occur one day before the raid on Korčula, distracting the Germans and tying up their reserve forces. A major obstacle for the Partisans Forces was the lack of appropriate vessels to conduct the raid: the Partisans had just four armed ships at their disposal for convoy protection duties while the transport vessels were too slow (4–5 knots (7.4–9.3 km/h; 4.6–5.8 mph)) to traverse the 64 nautical miles (119 kilometres) between Vis and Mljet in a single night. After Allied Forces declined to provide vessels for convoy protection, the Partisans allocated two armed ships for each of the raids. It was further decided to depart Vis a day earlier and first reach Lastovo where the raiding party would wait for the next night before making their way to Mljet itself. Sailing only under the cover of darkness was deemed a necessity to ensure the safety of the convoy and to avoid detection by German reconnaissance aircraft. Prior to the raid, the 11th Brigade Headquarters dispatched intelligence officer Ante Bogdanić to survey to situation on Mljet. He was followed on 16 April by a group of Partisans led by the 26th Division Operations officer Captain Bogdan Pecotić tasked with preparing the landing sites. Partisan battalions taking part in the raid were commanded by the 11th Brigade Commander Captain Milan Atlagić. Once on Mljet, he would be joined by Pecotić who would help him with decision making. Chief of Staff of the 26th Division, lieutenant colonel Ante Biočić, was responsible for overseeing the Mljet raid and was positioned on Lastovo from which he would maintain radio communications with the 11th Brigade Headquarters.