The F124 Sachsen class is a German Navy's class of air-defense frigates. The design of the hull is based on that of the F123 Brandenburg class but with enhanced stealth features designed to deceive an opponent's radar and acoustic sensors. The class incorporates an advanced multifunction radar APAR and a SMART-L long-range radar which is purported to be capable of detecting stealth aircraft and stealth missiles.

Although designated as frigates, they are comparable to destroyers in capability and were intended to replace the Navy's Lütjens class. They are similar to the Dutch De Zeven Provinciën class, in that both are based on the use of a common primary anti-air warfare system built around the APAR and SMART-L radars as well as the area-defence SM-2 Block IIIA and point-defence Evolved Sea Sparrow Missile (ESSM) surface-to-air missiles.

The German government contracted for three ships in June 1996 with an option on a fourth that was provisionally to have been named Thüringen, but the option for this fourth ship was not taken up. At €2.1 billion for the three ships, the class was one of the most expensive ship building programs of the German Navy.

Following the reunification of Germany in 1990 at the end of the Cold War, the German Navy continued the construction program of the former Bundesmarine (Federal Navy), which projected a fleet centered on destroyers and frigates. The Sachsen class was the second group of frigates to be built in the post-unification era, following the Brandenburg-class frigates laid down in the early 1990s. The three Sachsens were ordered to replace the old Lütjens-class destroyers that were then over thirty years old.

The ships of the Sachsen class are 132.15 meters (433 ft 7 in) long at the waterline and 143 m (469 ft 2 in) long overall. They have a beam of 17.44 m (57 ft 3 in) and a draft of 5 m (16 ft 5 in), though the draft increases to 7 m (23 ft 0 in) at the sonar array in the bulbous bow. They displace 5,690 long tons (5,780 t) at full load. Steering is controlled by a single roll-stabilized rudder; the ships have a turning radius of 570 m (1,870 ft). The frigates have a crew of 38 officers, 64 petty officers, and 140 enlisted sailors. They have accommodations for an additional thirteen officers and sailors as part of a squadron commander's staff, and they have crew provisions for female sailors. The ships can remain at sea for 21 days at a time.

The ships' hulls were designed on the pattern of the previous Brandenburg class to allow for great commonality of parts to reduce maintenance costs; they were built using MEKO modular construction and incorporate seven watertight compartments. The primary improvement over the earlier vessels is the significantly reduced radar signature. The ships were designed with a capacity for an extra 270 long tons (270 t) of weight, to allow for future additions of new weapons and sensors without compromising the ships' efficiency.

The ships of the Sachsen class are equipped with a combined diesel and gas (CODAG) propulsion system. The two operating shafts work independently. The diesel engines are installed in a non-walkable sound-proof capsule. The shafts drive two five-bladed variable-pitch propellers. The General Electric LM2500 PF/MLG gas turbine is rated at 31,500 shaft horsepower (23,500 kW) and the MTU 20V 1163 TB93 diesels provide a combined 20,100 brake horsepower (15,000 kW). The total 51,600 hp (38,500 kW) propulsion system provides a top speed of 29 knots (54 km/h; 33 mph); while operating the diesels only, the ships can cruise for 4,000 nautical miles (7,400 km; 4,600 mi) at a speed of 18 kn (33 km/h; 21 mph). The ships are equipped with four 1,000 kilowatt diesel generators that operate at 400 Volts (V) and 115 V.

Steering is controlled via the Rudder Roll System, which communicates information about the ship's position and rudder dampening signals, allowing the ships to maintain "almost unprecedented stability" in as high as sea state 5.