Core answer:
Human haploid cells are the gametes—sperm in males and oocytes (egg cells) in females. Each of these cells carries a single set of chromosomes (n = 23 in humans). Details:

• What is haploidy? A haploid cell has one complete set of chromosomes, half the diploid number found in most body (somatic) cells. In humans, the haploid number is 23.

• Which human cells are haploid? Only gametes (sperm and egg cells) are haploid in humans. All other somatic cells are diploid (46 chromosomes, or 2n).

• Why haploidy matters: Gametes are produced by meiosis to ensure that fertilization restores the diploid chromosome number in the zygote (46 chromosomes) when a haploid sperm and a haploid egg fuse.

succinct overview table:

• Cell type: Sperm (male gamete)
  • Chromosome set: 1 complete set (n = 23)
  • Context: Haploid
• Cell type: Egg (female gamete)
  • Chromosome set: 1 complete set (n = 23)
  • Context: Haploid
• Other human cells: Somatic cells (e.g., skin, muscle)
  • Chromosome set: 2 complete sets (2n = 46)
  • Context: Diploid

If you’d like, I can pull up a concise citation list or explain how haploid and diploid states arise during meiosis and fertilization.