USS Humboldt (AVP-21) was a United States Navy Barnegat-class small seaplane tender in commission from 1941 to 1947 that served in the Atlantic during World War II. She was briefly reclassified as a miscellaneous auxiliary and redesignated AG-121 during 1945. After the war, she was in commission in the United States Coast Guard as the cutter USCGC Humboldt (WAVP-372), later WHEC-372, from 1949 to 1969,