This dataset contains dissolved radiogenic neodymium (Nd) isotopes, rare earth element (REE) and trace metal (TM) concentrations of surface water in the South Pacific Ocean collected during the cross-Pacific GEOTRACES GP21 expedition (Chile-New Caledonia) with the German research vessel SONNE (SO289), which took place between February 23 and April 4, 2022. 20-40 L of surface seawater was collected either from the Niskin bottles attached to a stainless steel CTD rosette or from a trace-metal-clean underway tow-fish for Nd isotopes and REE concentrations. TM samples for dissolved manganese (dMn), dissolved iron (dFe), and dissolved aluminum (dAl) were collected from the tow-fish.Samples for Nd isotopes were pre-concentrated onboard by adsorption on Fe hydroxide precipitates and measured with a Neptune Plus Multicollector-Inductively Coupled Plasma Mass Spectrometer (MC-ICP-MS) after purification in the home laboratory. REE concentrations were pre-concentrated offline using a SeaFAST system and analyzed on a Thermo Element XR ICP-MS coupled with a CETAC "Aridus 2" desolvating nebulizer to reduce oxide formation. Dissolved Mn and Fe were pre-concentrated using SeaFast (SC-4 DX; ESI) and then measured on the same Thermo Element XR ICP-MS. Dissolved Al was analyzed shipboard using a Carey Eclipse fluorimeter. Phytoplankton pigment analysis (chlorophyll-a concentrations) were measured using a reverse-phase high-performance liquid chromatography (HPLC) (Dionex UltiMate 3000 LC system, Thermo Scientific).